Patent Publication Number: US-2022216072-A1

Title: Processing liquid supply apparatus and method of removing solids from processing liquid supply apparatus

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application claims priority to Korean Patent Application No. 10-2021-0001834, filed Jan. 7, 2021, the entire contents of which is incorporated herein for all purposes by this reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present disclosure relates to a processing liquid supply apparatus and a method of removing solids from the processing liquid supply apparatus. More specifically, the present disclosure relates to a processing liquid supply apparatus which supplies a processing liquid to a substrate processing apparatus and then recovers and regenerates the liquid and which has a flushing function for removing solids such as silica that are precipitated when the processing liquid is supplied. The present disclosure also relates to a method of removing the solids such as solid silica from the processing liquid supply apparatus. 
     2. Description of the Related Art 
     Ordinarily, various types of processing liquids are used in manufacturing processes of semiconductor devices, display panels, and the like. Concentration, temperature, flow rate, and the like of these processing liquids are adjusted to be suitable for process conditions through the processing liquid supply apparatus and then supplied to the substrate processing apparatus for processing a substrate. At this time, the processing liquid supply apparatus supplies a single processing liquid or a mixture of various processing liquids to the substrate processing apparatus. 
     For example, in a cleaning or etching process, a processing liquid such as an aqueous phosphoric acid solution is supplied, as an etching solution, to a surface of a substrate on which a silicon nitride film and a silicon oxide film are formed to selectively remove the silicon nitride film. 
     When the aqueous phosphoric acid solution is used for the selective etching of the silicon nitride film and the silicon oxide film, silica contained in the aqueous phosphoric acid solution is a factor that significantly affects the etching selectivity. 
     When the aqueous phosphoric acid solution as a processing liquid has an insufficient concentration of silica, the etching rate of the silicon oxide film increases, resulting in a decrease in the etching selectivity for the silicon nitride film. Conversely, when the silica concentration is excessively high, various problems occur such as selective etching not being performed properly or clogging of the filter. 
     Therefore, when performing the etching process using a processing liquid such as an aqueous phosphoric acid solution, it is important to control the concentration of silica contained in the processing liquid to fall within an appropriate range according to a processing purpose. 
     In particular, since there recently has been a transition to a new generation of semiconductors, etching equipment is also being switched from batch-type etching equipment to single wafer etching equipment. Batch-type etching equipment has disadvantages such as poor dispersion, issues with flow-related defects, and difficulty of controlling selectivity. Accordingly, single wafer etching equipment is being developed. 
     Single wafer etching equipment supplies a high-temperature phosphoric acid as a processing liquid to each chamber and has a processing liquid recycling system for recovering and recycling the used processing liquid. 
     When the temperature of the phosphoric acid as the processing liquid is lowered or the phosphoric acid as the processing liquid does not circulate in an application of such a processing liquid recycling system, liquid silica is precipitated as solid silica to become a particle source or become a cause of pipe clogging and sensing failure. 
     Accordingly, there are attempts to inhibit precipitation of silica by methods such as supplying a silica precipitation inhibitor, which suppresses silica precipitation. However, such an approach has problems in that it is not easy to control the etching selectivity when the silica precipitation inhibitor is added and solid precipitation of silica cannot be sufficiently inhibited when the processing liquid is exposed to the atmosphere during the process using the processing liquid (hereinafter referred to as “processing liquid process”). 
     Therefore, it is necessary to find a way to more effectively inhibit precipitation of silica or the like and to maintain a stable process yield. 
     DOCUMENTS OF RELATED ART 
     Patent Documents 
     
         
         (Patent Document 0001) Korean Patent Application Publication No. 10-2020-0115316 
         (Patent Document 0002) Korean Patent Application Publication No. 10-2019-0099814 
       
    
     SUMMARY OF THE INVENTION 
     The present disclosure has been made keeping in mind the above problems occurring in the prior art, and an objective of the present disclosure is to solve a problem of an unstable process yield due to solid precipitation of silica or the like. 
     In particular, the present disclosure proposes a method of removing precipitated solids such as silica by intensively flushing a solid precipitation region of a processing liquid supply apparatus where the silica is easily precipitated. 
     Furthermore, it is proposed to solve a problem of solids such as solid silica being precipitated and acting as a particle source and also to solve problems of pipe clogging in substrate processing facilities, sensing failure, or the like due to solid precipitations of silica or the like. 
     Objectives of the present disclosure are not limited to those mentioned above, and other objectives not mentioned will be clearly understood by those skilled in the art from the following description. 
     According to an embodiment of the present invention, a processing liquid supply apparatus may include: a flushing supply system configured to selectively supply a flushing fluid to a predetermined solid precipitation region of the processing liquid supply apparatus, a flushing control system configured to regulate a flow of the flushing fluid to flush the solid precipitation region, a flushing discharge system configured to discharge the processing liquid or flushing fluid from the solid precipitation region, and a controller configured to control the flushing supply system, the flushing control system, and the flushing discharge system such that the flushing of the solid precipitation region is controlled. 
     According to an embodiment of the present invention, a method of removing solids from the processing liquid supply apparatus may include: a processing liquid discharging step for discharging processing liquid remaining in a predetermined solid precipitation region of the processing liquid supply apparatus, a flushing step for performing flushing by supplying a flushing fluid to the solid precipitation region, and a flushing fluid discharging step for selectively discharging the used flushing fluid from the solid precipitation region. 
     According to an embodiment of the present invention, a processing liquid supply apparatus may include: a flushing fluid supply unit which supplies the flushing fluid containing at least one substance selected from the group consisting of HF, DIW, and an inert gas; a flushing fluid supply line for transporting the flushing fluid to a solid precipitation region; a flushing supply system including a flushing fluid supply valve for selectively supplying the flushing fluid from the flushing fluid supply unit to the flushing fluid supply line; a flushing control system including a flushing control valve for controlling a flow of the flushing fluid to the solid precipitation region to flush residual processing liquid with the flushing fluid; a flushing discharge system including a plurality of drain lines for discharging the residual processing liquid or the residual used flushing fluid in each of the solid precipitation regions, one or more manifold boxes which collect the processing liquid or flushing fluid discharged from a plurality of drain lines selected from among the plurality of drain lines and discharge the collected processing liquid or flushing fluid through one discharge line, and a buffer tank configured to receive and store the processing liquid or the flushing fluid from the one or more manifold boxes; and a controller which controls flushing of the solid precipitation region. By selectively controlling opening and closing of the flushing fluid supply line and opening and closing of the drain line, the controller enables flushing of the solid precipitation region with HF, DIW, and an inert gas in order or with DIW and an inert gas in order. 
     Advantageous Effects 
     The present disclosure enables effective maintenance of a process yield since the flushing process can be performed in the processing liquid supply apparatus while effectively removing solid precipitates such as silica and be immediately followed by supplying of the processing liquid. 
     In particular, in the present disclosure, removal of precipitated solids, such as silica, is made possible by intensive flushing of the solid precipitation region of the processing liquid supply apparatus where silica is easily precipitated. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objectives, features, and other advantages of the present disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a block diagram of an embodiment of a processing liquid supply apparatus to which the present disclosure is applied; 
         FIG. 2  shows an embodiment of a processing liquid supply unit of the processing liquid supply apparatus according to the present disclosure; 
         FIG. 3  shows an embodiment of a processing liquid recycling unit according to the present disclosure; 
         FIG. 4  is a block diagram of another embodiment of a processing liquid supply apparatus to which the present disclosure is applied; 
         FIG. 5  shows another embodiment of the processing liquid supply unit of the processing liquid supply apparatus according to the present disclosure; 
         FIG. 6  shows another embodiment of the processing liquid recycling unit according to the present disclosure; 
         FIG. 7  is a flowchart illustrating an embodiment of a method of removing solids from a processing liquid supply apparatus according to the present disclosure; 
         FIGS. 8A to 8C  show an embodiment in which flushing of a solid precipitation region of a silica supply system of a processing liquid supply apparatus is performed according to the present disclosure; 
         FIGS. 9A, 9B, and 10A to 10C  show an embodiment in which flushing of a solid precipitation region of an adjusting supply unit of a processing liquid supply apparatus is performed according to the present disclosure; 
         FIGS. 11A, 11B, and 12A to 12C  show an embodiment in which flushing of a solid precipitation region of a main supply unit of a processing liquid supply apparatus is performed according to the present disclosure; 
         FIGS. 13A, 13B, and 14A to 14C  show an embodiment in which flushing of a solid precipitation region of a processing liquid regeneration unit of a processing liquid supply apparatus is performed according to the present disclosure; and 
         FIGS. 15A to 15C  show an embodiment in which flushing of a solid precipitation region of a recovery unit of a processing liquid supply apparatus is performed according to the present disclosure. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     In order to describe the present disclosure, the operational advantages of the present disclosure, and the objectives achieved by the present disclosure, embodiments of the present disclosure are illustrated below, and the present disclosure is described with reference to the embodiments. 
     First, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprise”, “include”, “have”, and the like when used herein should be understood to specify the presence of stated features, numbers, steps, operations, elements, components, or combinations thereof but not to preclude the presence or addition of one or more other features, numbers, steps, operations, elements, components or combinations thereof. 
     In describing the present disclosure, when it is decided that a detailed description of a known configuration or function related to the disclosure makes the gist of the disclosure unclear, the detailed description is omitted. 
     The present disclosure discloses a processing liquid supply apparatus which supplies a processing liquid to a substrate processing apparatus and then recovers and regenerates the processing liquid and which has a flushing function of removing solids such as silica that are precipitated when the processing liquid is supplied. The present disclosure also discloses a method of removing the solids such as solid silica from the processing liquid supply apparatus. 
     First, a schematic configuration of a processing liquid supply apparatus to which the present disclosure is applied will be described through an embodiment, and a particular configuration of the present disclosure for inhibiting solid precipitation of silica and the like in such a processing liquid supply apparatus will be described through the embodiment. 
     The present disclosure may be applied to a processing liquid supply apparatus which supplies a processing liquid for a wet etching process, which removes a film on a surface of a substrate, or a cleaning process. The processing liquid supply apparatus supplies various processing liquids to a substrate processing apparatus in accordance with substrate processing conditions. 
     In the following examples, the processing liquid used in the substrate processing process is described as a high-temperature aqueous phosphoric acid solution containing silica, but this is limited for convenience of description. A processing liquid to be used in the processing liquid supply apparatus to which the present disclosure is applied may include at least one substance selected from the group consisting of hydrofluoric acid (HF), sulfuric acid (H 3 SO 4 ), hydrogen peroxide (H 2 O 2 ), nitric acid (HNO 3 ), phosphoric acid (H 3 PO 4 ), ozone water, SC-1 solution (a mixture of ammonium hydroxide (NH 4 OH), hydrogen peroxide (H 2 O 2 ), and water (H 2 O)), and the like and also may include other various substances that may be used in a substrate processing process. 
       FIG. 1  is a block diagram of an embodiment of a processing liquid supply apparatus to which the present disclosure is applied. 
     The processing liquid supply apparatus to which the present disclosure is applied may include a processing liquid supply unit  100 , a processing liquid recycling unit  200 , a controller (not shown), and the like. 
     The processing liquid supply unit  100  may include an adjusting supply unit  110  which adjusts and supplies a processing liquid in accordance with substrate processing conditions and a main supply unit  170  that supplies the processing liquid to a substrate processing apparatus  10 . 
     The processing liquid recycling unit  200  may include a recovery unit  210  that recovers the processing liquid from the substrate processing apparatus  10  and a processing liquid regeneration unit  250  which receives the recovered processing liquid from the recovery unit  210 , regenerates the processing liquid, and provides the regenerated processing liquid to the adjusting supply unit  110  of the processing liquid supply unit  100 . 
     In addition, the controller (not shown) may control supply, adjustment, recovery, regeneration, or disposal of the processing liquid of the processing liquid supply unit  100  and the processing liquid recycling unit  200 . 
     The present disclosure provides a flushing function for removing solid precipitates such as silica from a processing liquid supply apparatus such as one shown in  FIG. 1 . Embodiments of a processing liquid supply apparatus according to the present disclosure in which the flushing function has been added to the processing liquid supply apparatus shown in  FIG. 1  are described below with reference to  FIGS. 2 and 3 . 
     The processing liquid supply unit  100  and the processing liquid recycling unit  200  will be separately examined.  FIG. 2  is a case in which a flushing configuration is added to the processing liquid supply unit  100  in the processing liquid supply apparatus.  FIG. 3  shows a case in which a flushing configuration is added to the processing liquid recycling unit  200  in the processing liquid supply apparatus. 
     First, the processing liquid supply unit  100  to which the present invention is applied will be described. An embodiment of the present invention may include a flushing supply system  310 , a flushing control system, a flushing discharge system  350 , a controller (not shown), and the like in order to flush the processing liquid supply unit  100 . 
     The flushing supply system  310  may supply a flushing fluid to a part of the processing liquid supply unit  100  set as a solid precipitation region. As the flushing fluid, hydrogen fluoride (HF), deionized water (DIW), an inert gas, or the like may selectively be used alone or in combination. 
     The flushing supply system  310  may include a flushing fluid supply unit, a flushing fluid supply line, a flushing fluid supply valve, and the like. 
     The flushing fluid supply unit may be provided with a separate DIW supply unit  311 , HF supply unit  312 , and inert gas supply unit  313  depending on the flushing fluid used. Through the flushing fluid supply valve  315 , HF, DIW, or an inert gas may selectively be supplied to the flushing fluid supply line alone or in combination. 
     The flushing fluid supply line provides the flushing fluid to the set solid precipitation region in the processing liquid supply unit  100 . The supply line may be configured such that an amount of the flushing fluid supplied is adjusted in consideration of the solid precipitation region. For example, when a relatively small amount of flushing fluid supply is required, the flushing fluid may be supplied through a small supply line SS  316 , or when a relatively large amount of flushing fluid supply is required, the flushing fluid may be supplied through a large supply line BS  317 . 
     In addition, the flushing control system induces flushing of the corresponding solid precipitation region set in the processing liquid supply unit  100  with the flushing fluid provided from the flushing supply system  310 . To this end, the flushing control system may include a flushing control valve disposed in each of the solid precipitation regions. A description of the flushing control system will be provided together with a description of a detailed configuration of the processing liquid supply unit  100 . 
     The flushing discharge system  350  discharges the processing liquid remaining in the set solid precipitation region in the processing liquid supply unit  100  and discharges the flushing fluid used to perform flushing. 
     The flushing discharge system  350  may include drain lines HD 1  to HD 6 , one or more manifold boxes  351  and  353 , a buffer tank  355 , and the like. 
     The drain lines HD 1  to HD 6  are connected to the solid precipitation region and discharge the processing liquid or the flushing fluid, and for this purpose, may be provided in a number corresponding to the number of solid precipitation regions. 
     The manifold boxes  351  and  353  may collect processing liquid or flushing fluid discharged from a plurality of drain lines selected from among a plurality of drain lines and discharge the collected processing liquid or flushing fluid through one discharge line. 
     The buffer tank  355  may receive and store waste liquid from one or more manifold boxes  351  and  353  and discharge the waste liquid to the outside when a predetermined processing of the waste liquid is completed. 
     In particular, the flushing control system arranged to flush the set solid precipitation region in the processing liquid supply unit  100  of the present disclosure will be described while examining each configuration of the processing liquid supply unit  100 . 
     The processing liquid supply unit  100  includes a main supply unit  170  which supplies the processing liquid to the substrate processing apparatus  10  and an adjusting supply unit  110  which adjusts the processing liquid in accordance with substrate processing conditions and supplies adjusted processing liquid to the main supply unit  170 . 
     The adjusting supply unit  110  may be provided with a silica supply system  120  which supplies silica. The silica supply system  120  includes a silica supply unit  121  which supplies silica, a silica supply valve  122  for controlling a supply of silica from the silica supply unit  121 , and a silica-measuring tube  123  for measuring and supplying a predetermined amount of silica in accordance with the substrate processing conditions. 
     Since the silica always remains in the silica supply system  120 , solid silica may be precipitated due to various conditions such as exposure to air, and the precipitates may cause problems such as blocking of a tube or supplying a solid form of silica. 
     In particular, since the silica-measuring tube  123  is not a region where silica flows continuously, solid silica may easily be precipitated in the tube. Therefore, in the present disclosure, a region where the silica supply system  120  is disposed may be set as the solid precipitation region, and a flushing configuration may be arranged for the region to support flushing of the region. 
     The flushing control system disposed in the silica supply system  120  may include a front-end flushing control valve  321  and a rear-end flushing control valve  325 . 
     A flushing fluid supply line SS and a front end of the silica-measuring tube  123  of the silica supply system  120  may be connected to the front-end flushing control valve  321 . A multi-directional valve such as a three-way valve may be used as the front-end flushing control valve  321  to selectively supply the flushing fluid and the like. 
     In addition, a rear end of the silica-measuring tube  123 , a silica supply line  125 , and a drain line HD 1  may be connected to the rear-end flushing control valve  325 . A multi-directional valve such as a three-way valve may be used as the rear-end flushing control valve  325  to selectively perform supplying of silica, discharging of flushing fluid, and the like. 
     In addition, the controller may control supplying of silica to, discharging of silica from, and flushing of the silica supply system  120  through the flushing control system. 
     An adjusting supply unit  430  may be provided with an adjusting tank  140  for storing the processing liquid, individual substance supply pipes  141  and  142  for supplying each of the processing liquid substances such as phosphoric acid, DIW, or the like to the adjusting tank  140 , and an inert gas supply system  143  for providing a pressure to discharge the processing liquid stored in the adjusting tank  140 . As the inert gas, nitrogen gas (N 2 ) or the like may be used. 
     In addition, the adjusting supply unit  110  may be provided with an adjusting circulation line  131  for adjusting the processing liquid in accordance with the substrate processing conditions while self-circulating the processing liquid in the adjusting tank  140 . In the adjusting circulation line  131 , an adjusting line pump  132  for circulating the processing liquid in the adjusting tank  140 , an adjusting line heater  133  for heating the circulating processing liquid, and a measurement system for measuring a concentration or temperature of the processing liquid may be arranged. The measurement system may include a phosphoric acid concentration meter  134  for measuring a concentration of an aqueous phosphoric acid solution, a thermometer (not shown) for measuring a temperature of the aqueous phosphoric acid solution, and the like. The adjusting line pump  132  is a pump with strong chemical resistance. For example, a diaphragm pump may be used to transfer a small amount of processing liquid, and a bellows pump or a magnetic pump may be used to transfer a large amount of processing liquid. Alternatively, a metering pump may be used for precisely circulation of a predetermined amount of a mixed solution. 
     In addition, although not shown in  FIG. 2 , a control valve may be provided to perform self-circulation of the processing liquid through the adjusting circulation line  131  or discharge the adjusted processing liquid to the adjusted processing liquid supply pipe  111 . The control valve may be a three-way valve, a four-way valve, or the like. For example, when self-circulating the processing liquid, the control valve is closed to circulate the processing liquid through the adjusting circulation line  131 . When supplying the adjusted processing liquid, the control valve may be opened to discharge the adjusted processing liquid to the adjusted processing liquid supply pipe  111 . 
     A flow meter (not shown) may be provided in the adjusted processing liquid supply pipe  111  to measure an amount and flow rate of the adjusted processing liquid supplied. 
     The processing liquid adjusted in the adjusting supply unit  110  may be discharged through the adjusted processing liquid supply pipe  111  and provided to the main supply unit  170 . 
     The operation of the adjusting supply unit  110  may be controlled through a controller. The controller controls the silica supply system  120  to measure and selectively supply a predetermined amount of silica in accordance with the substrate processing conditions. In addition, the controller controls the individual substance supply pipes  141  and  142  to selectively supply the corresponding substance. The controller also controls adjustment of a phosphoric acid concentration and temperature of the processing liquid while selectively performing self-circulation of the processing liquid through the adjusting circulation line  131 . 
     Since the processing liquid does not continuously flow in the adjusting tank  140 , adjusting circulation line  131 , and the like in the adjusting supply unit  110 , the temperature of the processing liquid may decrease accordingly and solids of various processing liquids such as silica may be precipitated. 
     Therefore, in the present disclosure, the adjusting tank  140  and a selected section of the adjusting circulation line  131  may be set as solid precipitation regions, and a flushing configuration may be arranged for the regions to support flushing of the regions. 
     For this purpose, flushing control valves of the flushing control system may be disposed on a selected section of the adjusting circulation line  131  and at the input and output ends of the adjusting tank  140 . These flushing control valves may be controlled to operate organically with each other. 
     For example, a flushing control valve  331  may be disposed at the input end of the adjusting tank  140  of the adjusting circulation line  131 , and each flushing control valve  333  and  335  may be disposed at the front end and rear end of the adjusting line pump  132  of the adjusting circulation line  131  so that flushing of the adjusting tank  140  and the selected section of the adjusting circulation line  131  may be performed by an organic operation of these flushing control valves. 
     The flushing control valve  331  disposed at the input end of the adjusting circulation line  131  may be connected to a flushing fluid supply line BS, the input end of the adjusting tank  140 , the adjusting circulation line  131 , and the like. In addition, a discharge end of the adjusting tank  140 , an input end of the adjusting line pump  132 , a drain line HD 2 , a flushing fluid supply line SS, and the like may be connected to the flushing control valve  333  disposed at the front end of the adjusting line pump  132 . To the flushing control valve  335  disposed at the rear end of the adjusting line pump  132 , an input end of the adjusting circulation line  131 , an output end of the adjusting line pump  132 , a drain line HD 3 , a flushing fluid supply line SS, and the like may be connected. 
     Each of the flushing control valves may be a multi-directional valve according to the required input and output. For example, multi-directional valves such as a four-way valve may be used as the flushing control valves  333  and  335  disposed at the front and rear ends of the adjusting line pump  132  so that the supply and discharge of the processing liquid and the supply and discharge of the flushing fluid may be selectively performed. 
     In addition, the controller may control supplying of the processing liquid to, discharging of the processing liquid from, and flushing of the selected section of the adjusting circulation line  131  and the adjusting tank  140  through the flushing control system. 
     Next, a main supply unit  170  will be described. The main supply unit  170  may be provided with a main supply tank  180  for storing the adjusted processing liquid, a substance supply system  181  for supplying a processing liquid substance such as DIW or the like to the main supply tank  180 , and an inert gas supply system  183  for providing pressure to discharge the processing liquid stored in the main supply tank  180 . 
     In addition, the main supply unit  170  may be provided with a processing liquid supply pipe  171  which supplies the adjusted processing liquid from the main supply tank  180  to the substrate processing apparatus  10  and a processing liquid supply pipe pump  191  for supplying the processing liquid from the main supply tank  180  to the processing liquid supply pipe  171 . A processing liquid supply pipe filter  193  for final filtering of the processing liquid supplied to the substrate processing apparatus  10  may be provided in the processing liquid supply pipe  171 . 
     In addition, a flow meter (not shown) may be provided in the processing liquid supply pipe  171  to measure a supply amount and flow rate of the processing liquid supplied to the substrate processing apparatus  10 . 
     In addition, the main supply unit  170  may include a sampling line  173  for sampling the processing liquid supplied from the main supply tank  180  and a measurement system for measuring the processing liquid of the sampling line  173 . The measurement system may include a silica densitometer  175  for measuring a concentration of silica contained in the processing liquid. 
     In addition, a supplied processing liquid recovery line  190  for recovering a processing liquid not properly adjusted according to the measurement result of the sampled processing liquid may be provided. 
     The supplied processing liquid recovery line  190  may be connected to the main supply tank  180  to recover the processing liquid thereto based on the measured silica concentration. When necessary, a drain valve may be disposed on the supplied processing liquid recovery line  190  to dispose of processing liquid having a concentration exceeding a predetermined silica concentration by discharging the processing liquid to the outside. 
     The operation of the main supply unit  170  may be controlled through a controller. The controller controls a supply of the processing liquid from the main supply tank  180  to the substrate processing apparatus  10  through the processing liquid supply pipe  171 . The processing liquid supplied through the sampling line  173  may be sampled to check whether the processing liquid has been properly adjusted. For example, a silica concentration or temperature of the processing liquid may be measured, and on the basis of the measurement results, supply of silica to the adjusting supply unit  110  or a heating temperature may be controlled. In addition, when the sampled processing liquid does not meet a predetermined range of substrate processing conditions, the controller may recover the processing liquid supplied to the substrate processing apparatus  10  through the supplied processing liquid recovery line  190  or dispose of the processing liquid by draining the processing liquid to the outside. 
     Since the main supply unit  170  as described above intermittently supplies the processing liquid to the substrate processing apparatus  10 , the temperature of the processing liquid may decrease and solids of various processing liquids such as silica may be precipitated. 
     Therefore, in the present disclosure, the main supply tank of the main supply unit  170 , a selected section of the processing liquid supply pipe  171 , and a selected section of the sampling line  173  were set as solid precipitation regions, and a flushing configuration may be arranged for the region to support flushing of the regions. 
     For this purpose, flushing control valves of the flushing control system may be disposed on a selected section of the processing liquid supply pipe  171  and at the input and output ends of the main supply tank  180 . These flushing control valves may be controlled to operate organically with each other. In addition, a flushing control valve of the flushing control system may be disposed on the selected section of the sampling line  173  to perform flushing. 
     For example, a flushing control valve  341  may be disposed at the input end of the main supply tank  180  of the processing liquid recovery line  190 , and each flushing control valve  343  and  345  may be disposed at the front and rear ends of the processing liquid supply pipe pump  191  of the processing liquid supply pipe  171  so that flushing of the main supply tank  180  and the selected section of the processing liquid supply pipe  171  may be performed by an organic operation of these flushing control valves. 
     The flushing control valve  341  disposed at the input end of the main supply tank  180  may be connected to a flushing fluid supply line BS, the input end of the main supply tank  180 , the processing liquid recovery line  190 , and the like. In addition, a discharge end of the processing liquid supply pipe pump  191 , an input end of the processing liquid supply pipe pump  191 , a drain line HD 4 , a flushing fluid supply line SS, and the like may be connected to the flushing control valve  343  disposed at the front end of the processing liquid supply pipe pump  191 . To the flushing control valve  345  disposed at the rear end of the processing liquid supply pipe pump  191 , the processing liquid supply pipe  171 , an output end of the processing liquid supply pipe pump  191 , a drain line HD 5 , a flushing fluid supply line SS, and the like may be connected. 
     Each of the flushing control valves may be a multi-directional valve according to the required input and output. For example, multi-directional valves such as a four-way valve may be used as the flushing control valves  343  and  345  disposed at the front and rear ends of the processing liquid supply pipe pump  191  so that the supply and discharge of the processing liquid and the supply and discharge of the flushing fluid may be selectively performed. 
     In addition, the controller may control supplying of the processing liquid to, discharging of the processing liquid from, and flushing of the selected section of the processing liquid supply pipe  171  and the main supply tank  180  through the flushing control system. 
     In addition, in the selected section of the sampling line  173 , a front-end flushing control valve  347  may be disposed at the front end of the silica densitometer  175  on the sampling line  173  and a rear-end flushing control valve  349  may be disposed at the rear end of the silica densitometer  175  on the sampling line  173  to enable discharging of residual processing liquid in the sampling line  173  and flushing with the flushing fluid. 
     A flushing fluid supply line SS may be connected to the front-end flushing control valve  347  disposed at the front end of the silica densitometer  175 , and a drain line HD 6  may be connected to the rear-end flushing control valve  349  disposed at the rear end of the silica densitometer  175 . 
     In addition, the controller may control supplying of the processing liquid to, discharging of the processing liquid from, and flushing of the selected section of the sampling line  173  through the flushing control system. 
     Next, the processing liquid recycling unit  200  to which the present disclosure is applied will be described. 
     An embodiment of the present disclosure may include a flushing supply system  360 , a flushing control system, a flushing discharge system  390 , a controller (not shown), and the like in order to flush the processing liquid recycling unit  200 . 
     Since the flushing supply system  360  and the flushing discharge system  390  are similar to the description provided with reference to  FIG. 2  above, a description thereof will be omitted. 
     The flushing control system induces flushing of a corresponding solid precipitation region set in the processing liquid recycling unit  200  with the flushing fluid provided from the flushing supply system  360 . To this end, the flushing control system may include a flushing control valve disposed in each of the solid precipitation regions. A description of the flushing control system will be provided together with a description of a detailed configuration of the processing liquid recycling unit  200 . 
     The processing liquid recycling unit  200  may be spatially separated from the processing liquid supply unit  100  described above and disposed as different equipment. That is, in order to solve spatial limitations of a substrate processing facility, the processing liquid recycling unit  200  may be configured as an independent device separate from the processing liquid supply unit  100  and be disposed in a different place from the processing liquid supply unit  100 . 
     As described above, since the processing liquid supply unit  100  and the processing liquid recycling unit  200  may be spatially separated and disposed as different equipment, a configuration for flushing each unit may also be configured individually. 
     The processing liquid recycling unit  200  may include a recovery unit  210  which recovers used waste processing liquid from the substrate processing apparatus  10  and a processing liquid regeneration unit  250  which regenerates the recovered waste processing liquid recovered by the recovery unit  210  and supplies the regenerated processing liquid to the adjusting supply unit  110  of the processing liquid supply unit  100 . 
     The recovery unit  210  may include a waste processing liquid supply pipe  220  through which the waste processing liquid is supplied from the substrate processing apparatus  10  and a recovery tank  230  which is connected to the waste processing liquid supply pipe  220  and which temporarily stores the waste processing liquid. 
     In addition, the recovery unit  210  may be provided with a recovered processing liquid supply pipe  240  for supplying the waste processing liquid stored in the recovery tank  230  to the processing liquid regeneration unit  250  and a recovery pipe pump  241  for discharging the waste processing liquid stored in the recovery tank  230  to the recovered processing liquid supply pipe  240 . 
     In addition, the recovery unit  210  may be provided with a main filter  235  for filtering foreign substances when supplying the waste processing liquid to the processing liquid regeneration unit  250  through the recovered processing liquid supply pipe  240 . 
     The operation of the recovery unit  210  may be controlled by a controller. The controller may temporarily store the waste processing liquid in the recovery tank  230  of the recovery unit  210  and supply the waste processing liquid in the recovery tank  230  to the processing liquid regeneration unit  250  or dispose of the processing liquid by draining the processing liquid to the outside. 
     The recovery unit  210  recovers the used processing liquid from the substrate processing apparatus  10  and temporarily stores the liquid. The used processing liquid contains large amounts of various foreign substances, and solids of various processing liquids such as silica may be precipitated in the recovery unit  210  due to storage of such used processing liquid. 
     Therefore, in the present disclosure, a selected section such as the recovery tank  230  of the recovery unit  210  may be set as a solid precipitation region, and a flushing configuration may be arranged for the region to support flushing of the region. 
     For this purpose, flushing control valves of the flushing control system may be disposed at the front and rear ends of the recovery tank  230 . These flushing control valves may operate organically with each other to flush a selected section of the recovery unit  210 . 
     For example, a flushing control valve  385  for discharging the waste processing liquid to a drain line RD 3  may be provided on the waste processing liquid supply pipe  220  that receives the waste processing liquid from the substrate processing apparatus  10  and supplies the waste processing liquid to the recovery tank  230 . In addition, a flushing control valve  281  connected to a flushing fluid supply line BS to supply the flushing fluid to the recovery tank  230  may be disposed at the front end of the recovery tank  230 , and a flushing control valve  287  connected to an output end of the recovery tank  230 , the recovered processing liquid supply pipe  240 , a drain line RD 4 , and the like may be disposed. 
     In addition, the controller may control supplying of the processing liquid to, discharging of the processing liquid from, and flushing of the selected section of the recovery unit  210  and the recovery tank  230  through the flushing control system. 
     The waste processing liquid recovered by the recovery unit  210  may be filtered, supplied to the processing liquid regeneration unit  250 , and regenerated by the processing liquid regeneration unit  250  to an appropriate level for use. 
     The processing liquid regeneration unit  250  may include a regeneration tank  270  for storing the processing liquid supplied from the recovery unit  210 , and supplying of the processing liquid from the recovered processing liquid supply pipe  240  to the regeneration tank  270  may be controlled through the processing liquid supply valve  243 . 
     The processing liquid regeneration unit  250  may be provided with a processing liquid substance supply pipe  271  for supplying DIW to the regeneration tank  270  and an inert gas supply system  273  for providing pressure to discharge the processing liquid stored in the regeneration tank  270 . As the inert gas, nitrogen gas (N 2 ) or the like may be used. 
     In addition, the processing liquid regeneration unit  250  may be provided with a regeneration circulation line  261  for regenerating the processing liquid while self-circulating the processing liquid in the regeneration tank  270 . In the regeneration circulation line  261 , a regeneration line pump  262  for circulating the processing liquid, a regeneration line heater  263  for heating the circulating processing liquid, a measuring system for measuring a concentration or temperature of the processing liquid, and the like may be disposed. The measurement system may include a phosphoric acid concentration meter  264  for measuring a phosphoric acid moisture concentration of the processing liquid, a thermometer (not shown) for measuring a temperature of the processing liquid, and the like. 
     In addition, a regenerated liquid supply valve  266  for self-circulating the processing liquid through the regeneration circulation line  261  or for discharging the regenerated processing liquid to the regenerated processing liquid supply pipe  251  may be provided. A three-way valve, a four-way valve, or the like may be used as the regenerated liquid supply valve  266  to selectively circulate the processing liquid through the regeneration circulation line  261  or discharge the regenerated processing to the regenerated processing liquid supply pipe  251 . 
     In addition, a sub-filter  265  for filtering the processing liquid during self-circulation may be provided on the regeneration circulation line  261 . 
     Furthermore, a recovery line  255  for recovering the processing liquid supplied from the processing liquid regeneration unit  250  to the adjusting supply unit  110  through the regenerated processing liquid supply pipe  251  may be provided. A regenerated processing liquid supply valve  253  for controlling a supply of the regenerated processing liquid to the adjusting supply unit  110  may be disposed on the regenerated processing liquid supply pipe  251 , and a regenerated processing liquid recovery valve  257  for recovering the regenerated processing liquid to the recovery line  255  may also be disposed. The regenerated processing liquid supply valve  253  and the regenerated processing liquid recovery valve  257  may be replaced with one three-way valve. 
     The operation of the processing liquid regeneration unit  250  may be controlled through a controller. The controller enables regeneration of the processing liquid by controlling selective supplying of the waste processing liquid from the recovery unit  210  to the processing liquid regeneration unit  250 , controlling each substance supply pipe  271  to selectively supply a corresponding substance such as DIW and the like, and controlling adjustment of a phosphoric acid moisture concentration and temperature during self-circulation of the processing liquid through the regeneration circulation line  261 . 
     Since the processing liquid often does not continuously flow and instead stays in the regeneration tank  270 , regeneration circulation line  261 , and the like of the processing liquid regeneration unit  250 , the temperature of the processing liquid may decrease accordingly and solids of various processing liquids such as silica may be precipitated. 
     Therefore, in the present disclosure, the regeneration tank  270  and a selected section of the regeneration circulation line  261  are set as solid precipitation regions, and a flushing configuration may be arranged for the regions to support flushing of the regions. 
     For this purpose, flushing control valves of the flushing control system may be disposed on a selected section of the regeneration circulation line  261  and at the input and output ends of the regeneration tank  270 . These flushing control valves may be controlled to operate organically with each other. 
     For example, a flushing control valve  371  may be disposed at the input end of the regeneration tank  270  of the regeneration circulation line  261 , and each flushing control valve  373  and  375  may be disposed at the front end and rear end of the regeneration line pump  262  of the regeneration circulation line  261  so that flushing of the regeneration tank  270  and the selected section of the regeneration circulation line  261  may be performed by an organic operation of these flushing control valves. 
     The flushing control valve  371  disposed at the input end of the regeneration tank  270  may be connected to a flushing fluid supply line BS, the input end of the regeneration tank  270 , the regeneration circulation line  261 , and the like. In addition, a discharge end of the regeneration tank  270 , an input end of the regeneration line pump  262 , a drain line RD 1 , a flushing fluid supply line SS, and the like may be connected to the flushing control valve  373  disposed at the front end of the regeneration line pump  262 . To the flushing control valve  375  disposed at the rear end of the regeneration line pump  262 , an input end of the regeneration circulation line  261 , an output end of the regeneration line pump  262 , a drain line RD 2 , a flushing fluid supply line SS, and the like may be connected. 
     Each of the flushing control valves may be a multi-directional valve according to the required input and output. For example, multi-directional valves such as a four-way valve may be used as the flushing control valves  373  and  375  disposed at the front and rear ends of the regeneration line pump  262  so that the supply and discharge of the processing liquid and the supply and discharge of the flushing fluid may be selectively performed. 
     In addition, the controller may control supplying of the processing liquid to, discharging of the processing liquid from, and flushing of the selected section of the regeneration circulation line  261  and the regeneration tank  270  through the flushing control system. 
     As described above, in the present disclosure, regions in which solid precipitates such as silica are generated may be set in each of the processing liquid supply unit  100  and processing liquid recycling unit  200 , and the present disclosure proposes a processing liquid supply apparatus to which a flushing function has been added by arranging a configuration for flushing these regions. 
     The processing liquid supply unit  100  of  FIG. 2  and the processing liquid recycling unit  200  of  FIG. 3  may be arranged in different spaces, and accordingly, two sets of flushing supply system and flushing discharge system for performing flushing have been described as being arranged in the processing liquid supply unit  100  and the processing liquid recycling unit  200 , respectively. However, this depends on an arrangement of the processing liquid supply equipment. When the processing liquid supply unit and the processing liquid recycling unit are arranged to be connected in one space, the configuration for performing flushing may also be arranged therewith. 
     Furthermore, in the processing liquid supply apparatus described above with reference to  FIG. 1 , one adjusting supply unit  110  may be disposed in the processing liquid supply unit  100 , and one processing liquid regeneration unit  250  may be disposed in the processing liquid recycling unit  200 . However, the number of the adjusting supply unit  110  of the processing liquid supply unit  100  and the number of the processing liquid regeneration unit  250  of the processing liquid recycling unit  200  may be changed as necessary. 
     In this regard,  FIG. 4  shows a block diagram of another embodiment of a processing liquid supply apparatus to which the present disclosure is applied. 
     The embodiment shown in  FIG. 4  is similar to the embodiment shown in  FIG. 1  discussed above in terms of basic configuration. However, the processing liquid supply unit  400  includes two adjusting supply units  410  arranged in parallel, and the processing liquid recycling unit  500  includes two processing liquid regeneration units  550  arranged in parallel. 
     Through the parallel arrangement of the plurality of adjusting supply units  410 , any one adjusting supply unit  410  may supply the main supply unit  470  with a processing liquid whose concentration and temperature are adjusted in accordance with substrate processing conditions while at the same time, the other adjusting supply unit  410  may adjust the concentration and temperature of the processing liquid in accordance with the substrate processing conditions. 
     In addition, through the parallel arrangement of the plurality of processing liquid regeneration units  550 , any one processing liquid regeneration unit  550  may receive used processing liquid from the recovery unit  510  and regenerate the used processing liquid while at the same time, the other processing liquid regeneration unit  550  may supply the regenerated processing liquid to any one of the plurality of adjusting supply units  410 . 
     Through the configuration of the plurality of adjusting supply units  410  and the plurality of processing liquid regeneration units  550 , continuous adjustment and regeneration of processing liquid may be performed and at the same time, the adjusted processing liquid may continuously be supplied to the substrate processing apparatus, thereby increasing efficiency of supplying processing liquid. 
     The present disclosure provides a flushing function for removing solid precipitates such as silica from a processing liquid supply apparatus such as one shown in  FIG. 4 . Embodiments of a processing liquid supply apparatus according to the present disclosure in which the flushing function has been added to the processing liquid supply apparatus shown in  FIG. 4  will be examined separately with reference to two embodiments: the processing liquid supply unit  400  shown in  FIG. 5  and the processing liquid recycling unit  500  shown in  FIG. 6 . 
     For the embodiment of the processing liquid supply unit  400  of  FIG. 5 , a description of parts which overlap with the embodiment of the processing liquid supply unit  100  of  FIG. 2  described above will be omitted. Similarly, for the embodiment of the processing liquid recycling unit  500  of  FIG. 6 , a description of parts which overlap with the embodiment of the processing liquid recycling unit  200  of  FIG. 3  described above will be omitted. 
     First, the processing liquid supply unit  400  to which the present disclosure is applied will be described. 
     A flushing supply system  610 , a flushing control system, a flushing discharge system  650 , a controller (not shown), and the like may be provided with the processing liquid supply unit  400  of  FIG. 5  in order to flush the processing liquid supply unit  400 . 
     The flushing supply system  610  may be provided with a separate DIW supply unit  611 , HF supply unit  612 , and inert gas supply unit  613  depending on the flushing fluid used. Through a flushing fluid supply valve  615 , HF, DIW, or an inert gas may selectively be supplied to the flushing fluid supply line alone or in combination. 
     The flushing fluid supply line provides flushing fluid to a set solid precipitation region in processing liquid supply unit  400 . Depending on a supply amount of flushing fluid required, a small supply line SS  616  or a large supply line BS  617  may be provided. 
     In addition, the flushing control system induces flushing of the corresponding solid precipitation region set in the processing liquid supply unit  400  with the flushing fluid provided from the flushing supply system  610 . To this end, the flushing control system may include a flushing control valve disposed in each of the solid precipitation regions. A description of the flushing control system will be provided together with a description of a detailed configuration of the processing liquid supply unit  400 . 
     The flushing discharge system  650  discharges the processing liquid remaining in the set solid precipitation region in the processing liquid supply unit  400  and discharges the flushing fluid used to perform flushing. The flushing discharge system  350  may include drain lines HD 1  to HD 8 , one or more manifold boxes  651  and  653 , a buffer tank  655 , and the like. 
     The drain lines HD 1  to HD 8  are connected to the solid precipitation region and discharge the processing liquid or the flushing fluid, and the number of drain lines provided may be adjusted according to number of set solid precipitation regions. 
     The manifold boxes  651  and  653  may collect processing liquid or flushing fluid discharged from a plurality of drain lines selected from among a plurality of drain lines and discharge the collected processing liquid or flushing fluid through one discharge line. The buffer tank  355  may receive and store waste liquid from one or more manifold boxes  651  and  653  and discharge the waste liquid to the outside when a predetermined processing of the waste liquid is completed. 
     The flushing control system arranged to flush the set solid precipitation region in the processing liquid supply unit  400  of the present disclosure will be described while examining each configuration of the processing liquid supply unit  400 . 
     The processing liquid supply unit  400  includes a main supply unit  470  which supplies the processing liquid to the substrate processing apparatus  10  and an adjusting supply unit  410  which adjusts the processing liquid in accordance with substrate processing conditions and supplies adjusted processing liquid to the main supply unit  470 . 
     The adjusting supply unit  410  may include a first adjusting supply unit  430 , a second adjusting supply unit  450 , and a silica supply system  420 . The silica supply system  420  may selectively supply silica to each of the first adjusting supply unit  430  and the second adjusting supply unit  450 . 
     The silica supply system  420  is similar to that shown in  FIG. 2  above, and the area in which the silica supply system  420  is disposed may be set as the solid precipitation region, and a flushing configuration may be arranged for the region to support flushing of the region. 
     As a configuration for flushing the silica supply system  420 , the flushing control system may include a front-end flushing control valve  621  and a rear-end flushing control valve  625 . 
     A silica supply line  425  for supplying silica to the first adjusting supply unit  430  and a silica supply line  427  for supplying silica to the second adjusting supply unit  450  may be connected to the rear-end flushing control valve  625 , which may be controlled to selectively supply silica to the first adjusting supply unit  430  and the second adjusting supply unit  450 . 
     The controller may control supplying of silica to, discharging of silica from, and flushing of the silica supply system  420  through the flushing control system. 
     Each of the first adjusting supply unit  430  and the second adjusting supply unit  450  has a configuration similar to that of the adjusting supply unit  110  of the embodiment shown in  FIG. 2 . 
     The processing liquid adjusted by the adjusting supply unit  410  may be selectively discharged from the first adjusting supply unit  430 , the second adjusting supply unit  450 , or both through the adjusted processing liquid supply pipe  411  and provided to the main supply unit  470 . 
     The operation of the adjusting supply unit  410  may be controlled through the controller. The controller controls the silica supply system  420  to measure a supply amount of silica and selectively supply a predetermined amount of silica to the first adjusting supply unit  430  and the second adjusting supply unit  450  in accordance with the substrate processing conditions. In addition, the controller controls the individual substance supply pipes  441 ,  442 ,  461 , and  462  to selectively supply the corresponding substance. The controller also controls adjustment of a phosphoric acid concentration and temperature of the processing liquid while selectively performing self-circulation of the processing liquid through a first adjusting circulation line  431  or a second adjusting circulation line  451 . 
     In some embodiments, the controller controls the adjusting supply units such that one of either the first adjusting supply unit  430  or the second adjusting supply unit  450  adjusts the processing liquid and the other supplies the processing liquid to the main supply unit  470  or receives the processing liquid from the processing liquid regeneration unit  550 . 
     In addition, in the embodiment shown in  FIG. 5 , a solid precipitation region may be set for each of the first adjusting supply unit  430  and the second adjusting supply unit  450 , and a flushing configuration may be arranged for each solid precipitation region. 
     For example, a first adjusting tank  440  and a selected section of the first adjusting circulation line  431  of the first adjusting supply unit  430  may be set as solid precipitation regions, and a flushing configuration may be arranged for the regions. In addition, a second adjusting tank  460  and a selected section of the second adjusting circulation line  451  of the second adjusting supply unit  450  may be set as solid precipitation regions, and a flushing configuration may be arranged for the regions. 
     For each solid precipitation region set in the first adjusting supply unit  430  and the second adjusting supply unit  450 , a flushing control valve of the flushing control system such as the one described above through the embodiment shown in  FIG. 2  may be disposed. The controller may control these flushing control valves to operate organically with each other to enable supplying of processing liquid to, discharging of processing liquid from, and flushing of each of the solid precipitation regions. 
     The main supply unit  470  will be described hereinafter. The main supply unit  470  has a configuration similar to that shown in  FIG. 2 . The main supply tank  480  of the main supply unit  470 , a selected section of a processing liquid supply pipe  471 , and a selected section of a sampling line  473  may be set as solid precipitation regions, and a flushing configuration may be arranged for the regions to support flushing of the regions. 
     Since flushing control valves of the flushing control system disposed in these solid precipitation regions have a configuration similar to those of  FIG. 2 , a description thereof will be omitted. 
     In addition, the controller may control supplying of the processing liquid to, discharging of the processing liquid from, and flushing of the selected section of the processing liquid supply pipe  471 , the main supply tank  480 , and the selected section of the sampling line  472  through the flushing control system. 
     Next, the processing liquid recycling unit  500  to which the present disclosure is applied will be described. 
     A flushing supply system  660 , a flushing control system, a flushing discharge system  690 , a controller (not shown), and the like may be provided with the processing liquid recycling unit  500  of  FIG. 6  in order to flush the processing liquid recycling unit  500 . 
     Since the flushing supply system  660  and the flushing discharge system  690  are similar to those of the other embodiments described above, a description thereof will be omitted. 
     The flushing control system induces flushing of a corresponding solid precipitation region set in the processing liquid recycling unit  500  with the flushing fluid provided from the flushing supply system  660 . To this end, the flushing control system may include a flushing control valve disposed in each of the solid precipitation regions. A description of the flushing control system will be provided together with a description of a detailed configuration of the processing liquid recycling unit  500 . 
     The processing liquid recycling unit  500  may include a recovery unit  510  which recovers used waste processing liquid from the substrate processing apparatus  10  and a processing liquid regeneration unit  550  which regenerates the recovered waste processing liquid recovered by the recovery unit  510  and supplies the regenerated processing liquid to the adjusting supply unit  410  of the processing liquid supply unit  400 . 
     The recovery unit  510  is similar to the recovery unit  210  of  FIG. 3  discussed above. The controller may control to temporarily store the waste processing liquid in the recovery tank  530  of the recovery unit  510  and supply the waste processing liquid of the recovery tank  530  to either a first processing liquid regeneration unit  560  or a second processing liquid regeneration unit  580  of the processing liquid regeneration unit  550  according to operating conditions of the regeneration units. 
     In the present disclosure, a selected section such as the recovery tank  530  of the recovery unit  510  may be set as a solid precipitation region, and a flushing configuration may be arranged for the region to support flushing of the region. 
     Since flushing control valves of the flushing control system disposed in these solid precipitation regions have a configuration similar to those of  FIG. 3 , a description thereof will be omitted. 
     The waste processing liquid recovered by the recovery unit  510  may be filtered, supplied to the processing liquid regeneration unit  550 , and regenerated by the processing liquid regeneration unit  550  to an appropriate level for use. 
     The processing liquid regeneration unit  500  may include the first processing liquid regeneration unit  560  and the second processing liquid regeneration unit  580 . The first processing liquid regeneration unit  560  and the second processing liquid regeneration unit  580  may be arranged in parallel and may be individually operated at the same time or at different times. 
     The first processing liquid regeneration unit  560  and the second processing liquid regeneration unit  580  may regenerate the processing liquid according to regeneration conditions and then selectively provide the regenerated processing liquid to the adjusting supply unit  410  through the regenerated processing liquid supply pipe  551 . Each of the first processing liquid regeneration unit  560  and the second processing liquid regeneration unit  580  has a configuration similar to that of the processing liquid regeneration unit  250  of  FIG. 3  described above. 
     Furthermore, when the adjusting supply unit  410  includes the first adjusting supply unit and the second adjusting supply unit, the processing liquid regeneration unit  550  may provide the regenerated processing liquid to any one of the first adjusting supply unit and the second adjusting supply unit according to the operating conditions of the adjusting supply units. Alternatively, the processing liquid regeneration unit  550  may supply the regenerated processing liquid only to the first adjusting supply unit. 
     The operation of the processing liquid regeneration unit  550  may be controlled through a controller. The controller enables regeneration of the processing liquid by controlling selective supplying of the waste processing liquid from the recovery unit  510  to the first processing liquid regeneration unit  560 , the second processing liquid regeneration unit  580 , or both, controlling each substance supply pipe  571  and  591  to selectively supply a corresponding substance such as DIW and the like, and controlling adjustment of a phosphoric acid moisture concentration and temperature during self-circulation of the processing liquid through a first regeneration circulation line  561  and a second regeneration circulation line  581 . 
     In some embodiments, the controller controls the processing liquid regeneration units such that one of either the first processing liquid regeneration unit  560  or the second processing liquid regeneration unit  580  regenerates the processing liquid and the other supplies the regenerated processing liquid to the adjusting supply unit  410  or receives the waste processing liquid from the recovery unit  510 . 
     In addition, in the embodiment shown in  FIG. 6 , a selected area on the first processing liquid regeneration unit  560  and the second processing liquid regeneration unit  580  may be set as solid precipitation regions, and a flushing configuration may be arranged for the regions. 
     For example, a first regeneration tank  570  and a selected section of the first regeneration circulation line  561  of the first processing liquid regeneration unit  560  may be set as solid precipitation regions, and a flushing configuration may be arranged for the regions. In addition, a second regeneration tank  590  and a selected section of the second regeneration circulation line  581  of the second processing liquid regeneration unit  580  may be set as solid precipitation regions, and a flushing configuration may be arranged for the regions. 
     In addition, the controller may control supplying of the processing liquid, discharging of the processing liquid, and flushing through the flushing control system disposed in the first processing liquid regeneration unit  560  and the second processing liquid regeneration unit  580 . 
     In the present disclosure, solid precipitates such as silica may be effectively removed by arranging the flushing configuration in the processing liquid supply apparatus as described above. 
     Furthermore, the present disclosure proposes a method of removing solids from the processing liquid supply apparatus through the processing liquid supply apparatus having a flushing function as described above. The method will be described hereinafter. 
     The method of removing solids from the processing liquid supply apparatus according to the present disclosure roughly includes: a processing liquid discharging step for discharging processing liquid remaining in a predetermined solid precipitation region of the processing liquid supply apparatus, a flushing step for performing flushing by supplying a flushing fluid to the solid precipitation region, and a flushing fluid discharging step for selectively discharging the flushing fluid that was used to perform flushing from the solid precipitation region. 
       FIG. 7  is a flowchart illustrating an embodiment of a method of removing solids from a processing liquid supply apparatus according to the present disclosure. 
     First, in order to perform flushing, a supply of the processing liquid to the processing liquid supply apparatus may be stopped (S 110 ), and the processing liquid remaining in the processing liquid supply apparatus may be discharged (S 120 ). 
     After discharging the residual processing liquid, flushing may be performed by supplying a flushing fluid to the solid precipitation region. The flushing may be performed by supplying various flushing fluids in a sequential order. 
     First, a flushing fluid containing HF may be supplied to the corresponding solid precipitation region (S 130 ) to perform flushing through which solid precipitates adhered to pipes and the like are removed. Then, the flushing fluid may be discharged through a drain line (S 140 ). 
     The flushing fluid containing HF may be an aqueous solution of HF whose concentration is adjusted considering a type of precipitate to be removed, characteristics of the solid precipitation region to be flushed, and the like. In addition, when flushing with HF is not appropriate due to the material characteristics of the solid precipitation region of the processing liquid supply apparatus to be flushed, the process of performing flushing with the flushing fluid containing HF may be removed. 
     Next, flushing may be performed by supplying DIW as a flushing fluid to the corresponding solid precipitation region (S 150 ), and the flushing fluid may be discharged through a drain line (S 160 ). The DIW as the flushing fluid can remove precipitates remaining on the pipes and the like. At the same time, since HF may remain in the pipes and the like due to the previously performed flushing with HF, flushing with DIW can dilute and remove the HF. 
     Finally, flushing may be performed by supplying an inert gas as a flushing fluid to the corresponding solid precipitation region (S 170 ), and impurities may be discharged through a drain line along with the inert gas (S 180 ). 
     Since flushing of the solid precipitation region was performed with various flushing fluids, DIW and the like may remain in the pipes in addition to any floating particles that did not get discharged. Supplying the inert gas as the flushing fluid at a certain level of pressure can remove the DIW, floating particles, and the like. In particular, the residual DIW and the like may affect a concentration of processing liquids supplied thereafter. By evaporating or discharging any residual flushing fluids such as the DIW, the solid precipitation region where the flushing was performed may be made into a completely empty space. 
     Furthermore, depending on circumstances, a cycle of flushing with the flushing fluid containing hydrogen fluoride and flushing with DIW as the flushing fluid may be repeated, and flushing with an inert gas as the flushing fluid may be performed at the end. 
     When the flushing of the corresponding solid precipitation region is completed, supplying of the processing liquid through the processing liquid supply apparatus may be resumed (S 190 ) to supply the processing liquid to the substrate processing apparatus. 
     The present disclosure enables effective removal of solid precipitates such as silica from the processing liquid supply apparatus through such a flushing process. 
     Hereinafter, a process of performing flushing according to the present disclosure for each part set as a solid precipitation region on the processing liquid supply device will be described. 
       FIGS. 8A to 8C  show an embodiment in which flushing is performed according to the present disclosure on a region where a silica supply system for supplying silica to a processing liquid supply apparatus is disposed. 
     The silica supply system  420  of  FIGS. 8A to 8C  is the silica supply system  420  disposed in the processing liquid supply unit  400  of  FIG. 5 . A selected predetermined section including a silica-measuring tube  423  may be set as a solid precipitation region, and flushing may be performed on the region. 
     The controller stops the supply of silica from the silica supply system  420  and discharges the silica remaining in the solid precipitation region including the silica-measuring tube  423  through the drain line HD 1  as shown in  FIG. 8A . At this time, a multi-directional valve may be used as the flushing control valve  625  of the flushing control system to selectively stop the supply of silica to the adjusting supply unit of the silica supply system  420  while opening the drain line HD 1  to discharge the residual silica. 
     The drain line HD 1  may be combined with several other drain lines through the manifold box  651  of the flushing discharge system  650 . The residual silica discharged through the drain line HD 1  may be stored in the buffer tank  655 , subjected to predetermined processing, and discharged to the outside. 
     When the silica remaining in the solid precipitation region including the silica-measuring tube  423  gets discharged, as shown in  FIG. 8B , the controller may control the flushing fluid supply valve  615  to supply DIW from the DIW supply unit  611  of the flushing supply system  610  to the solid precipitation region including the silica-measuring tube  423 . The DIW may be controlled to be supplied through the flushing supply line SS  616  because the DIW does not need to be supplied in a large amount. 
     When the DIW is supplied to the solid precipitation region including the silica-measuring tube  423  as the flushing fluid, solid precipitates such as silica remaining in the solid precipitation region including the silica-measuring tube  423  may be removed due to the flow and pressure of the flushing fluid. The controller controls the flushing control valve  625  to discharge the DIW used as the flushing fluid, which contains impurities such as solids as a result of flushing, through the drain line HD 1 . 
     Depending on circumstances, the controller may first perform flushing with a flushing fluid containing HF prior to performing flushing using the DIW as the flushing fluid. 
     When flushing using a flushing fluid such as DIW is completed, as shown in  FIG. 8C , the controller may control the flushing fluid supply valve  615  to supply an inert gas as the flushing fluid from the inert gas supply unit  613  to the solid precipitation region including the silica-measuring tube  423  and to open the drain line HD 1  for discharging. 
     Impurities, DIW, and the like remaining in the solid precipitation region including the silica-measuring tube  423  may be discharged through the drain line HD 1  by the pressure of the inert gas supplied. These flushing fluids and impurities may be stored in the buffer tank  655  of the flushing discharge system  650  when discharged through the drain line HD 1  and may be discharged to the outside after being subjected to a predetermined processing process. 
     Through such a flushing process, solid precipitates, impurities, or the like may be removed from the solid precipitation region including the silica-measuring tube  423 . In addition, the flushing fluids may also be completely removed using the inert gas, thereby enabling supplying of a high-quality processing solution immediately after flushing. 
       FIGS. 9 and 10  show an embodiment in which flushing of a solid precipitation region of an adjusting supply unit of a processing liquid supply apparatus is performed according to the present disclosure. 
     The adjusting supply unit  430  shown in  FIGS. 9 and 10  is the first adjusting supply unit  430  disposed in the processing liquid supply unit  400  of  FIG. 5 . The first adjusting tank  440  and the selected section of the first adjusting circulation line  431  may be set as solid precipitation regions, and flushing may be performed on the regions. 
     The controller stops the supply of processing liquid from the first adjusting supply unit  430  and discharges the processing liquid remaining in the first adjusting tank  440  and the first adjusting circulation line  431  through the drain lines HD 2  and HD 3  as shown in  FIG. 9A . At this time, a four-way valve may be used as the flushing control valves  633   a  and  635   a  of the flushing control system so that the valves may be controlled to circulate the processing liquid of the first adjusting tank  440  and the first adjusting circulation line  431  and discharge the processing liquid through the drain lines HD 2  and 
     The drain lines HD 2  and HD 3  may be combined through the manifold box  651  of the flushing discharge system  650 . The discharged processing liquid may be stored in the buffer tank  655 , subjected to predetermined processing, and discharged to the outside. 
     When the processing liquid remaining in the solid precipitation regions of the first adjusting supply unit  430  gets discharged, as shown in  FIG. 9B , the controller may control the flushing control valve  331  disposed at the input end of the first adjusting tank  440  of the first adjusting circulation line  431  to supply the DIW as the flushing fluid to the solid precipitation regions of the first adjusting supply unit  430 . At this time, since a large amount of DIW needs to be supplied to the first adjusting tank  440  of the first adjusting supply unit  430  and the like, the DIW may be supplied through the flushing fluid supply line BS  617  to enable supplying of a large amount of the flushing fluid. 
     In addition, the controller may supply the DIW as the flushing fluid to the first adjusting tank  440  and the first adjusting circulation line  431 , circulate the flushing fluid, and control the flushing control valves  633   a  and  635   a  to discharge the flushing fluid through the drain lines HD 2  and HD 3 . 
     By performing comprehensive flushing of the first adjusting tank  440  and the first adjusting circulation line  431  with the DIW as the flushing fluid, solid precipitates such as silica and impurities may be primarily removed. 
     Next, the controller performs flushing of solid precipitation regions where solid precipitates such as silica may easily be generated. Since accumulation of solid precipitates and impurities may be concentrated near the drain lines for discharging the processing liquid or flushing fluid, intensive flushing may be performed on these solid precipitation regions. 
     In this regard, as shown in  FIG. 10A , the controller may control supplying of the flushing fluid containing HF from the HF supply unit  612  to the flushing control valves  633   a  and  635   a  disposed at the front and rear ends of the adjusting line pump  432 , respectively, through the flushing fluid supply line SS  616 . In some embodiments, an aqueous HF solution whose concentration of HF is adjusted considering the precipitates, impurities, or the like to be removed may be supplied as the flushing fluid. 
     In addition, the controller may perform intensive flushing near the drain lines by controlling the flushing fluid containing HF to be supplied and discharged through the drain lines HD 2  and HD 3  at the same time. 
     HF or the like remaining in the corresponding region after flushing with the flushing fluid containing HF affects supplying of a processing liquid thereafter. Therefore, as shown in  FIG. 10B , the controller may control the DIW to be supplied from the DIW supply unit  611  through the flushing fluid supply line SS  616  as the flushing fluid. In addition, while supplying the DIW as the flushing fluid, the controller may control the DIW to be discharged through the drain lines HD 2  and HD 3 . 
     Residual impurities, HF, or the like may be discharged using the DIW as the flushing fluid. Next, as shown in  FIG. 10C , the controller may control the inert gas to be supplied from the inert gas supply unit  613  through the flushing fluid supply line SS  616  as the flushing fluid and be discharged through the drain lines HD 2  and HD 3 . 
     Residual impurities, DIW, or the like may be discharged by pressure of the inert gas, and at the same time, any residual DIW may be removed by evaporation. 
     Through such a flushing process, solid precipitates, impurities, or the like may be removed from the solid precipitation regions of the first adjusting supply unit  430 . In addition, the flushing fluids may also be completely removed using the inert gas, thereby enabling supplying of a high-quality processing solution immediately after flushing. 
       FIGS. 11 and 12  show an embodiment in which flushing of a solid precipitation region of a main supply unit of a processing liquid supply apparatus is performed according to the present disclosure. 
     The adjusting supply unit  470  shown in  FIGS. 11 and 12  is the main supply unit  470  disposed in the processing liquid supply unit  400  of  FIG. 5 . The main supply tank  480 , the selected section of the processing liquid supply pipe  471 , and the selected section of the sampling line  473  may be set as solid precipitation regions, and flushing may be performed on the regions. 
     The controller stops the supply of processing liquid from the main supply unit  470  and discharges the processing liquid remaining in the main supply tank  480  and the processing liquid supply pipe  471  through the drain lines HD 6  and HD 7  as shown in  FIG. 11A . At this time, a four-way valve may be used as the flushing control valves  643  and  645  of the flushing control system so that the valves may be controlled to circulate the processing liquid of the main supply tank  480  and the processing liquid supply pipe  471  and discharge the processing liquid through the drain lines HD 6  and 
     When the processing liquid remaining in the solid precipitation regions of the main supply unit  470  gets discharged, as shown in  FIG. 11B , the controller may control the flushing control valve  641  disposed at the input end of the main supply tank  480  of the recovery line  490  to supply the DIW as the flushing fluid to the solid precipitation regions of the main supply unit  470 . At this time, since a large amount of DIW needs to be supplied to the main supply tank  480  of the main supply unit  470  and the like, the DIW may be supplied through the flushing fluid supply line BS  617  to enable supplying of a large amount of the flushing fluid. 
     In addition, the controller may supply the DIW as the flushing fluid to the main supply tank  480  and the recovery line  490 , circulate the flushing fluid, and control the flushing control valves  643  and  645  to discharge the flushing fluid through the drain lines HD 6  and 
     By performing comprehensive flushing of the main supply tank  480  and the recovery line  490  with the DIW as the flushing fluid, solid precipitates such as silica and impurities may be primarily removed. 
     Next, the controller may perform flushing of solid precipitation regions where solid precipitates such as silica may easily be generated. Since accumulation of solid precipitates and impurities may be concentrated near the drain lines for discharging the processing liquid or flushing fluid, intensive flushing may be performed on these solid precipitation regions. 
     In this regard, as shown in  FIG. 12A , the controller may control supplying of the flushing fluid containing HF from the HF supply unit  612  to the flushing control valves  643  and  645  disposed at the front and rear ends of the processing liquid supply pipe pump  491 , respectively, through the flushing fluid supply line SS  616 . In some embodiments, an aqueous HF solution whose concentration of HF is adjusted considering the precipitates, impurities, or the like to be removed may be supplied as the flushing fluid. 
     In addition, the controller may perform intensive flushing near the drain lines by controlling the flushing fluid containing HF to be supplied and discharged through the drain lines HD 6  and HD 7  at the same time. 
     HF or the like remaining in the corresponding region after flushing with the flushing fluid containing HF affects supplying of a processing liquid thereafter. Therefore, as shown in  FIG. 12B , the controller may control the DIW to be supplied from the DIW supply unit  611  through the flushing fluid supply line SS  616  as the flushing fluid. In addition, while supplying the DIW as the flushing fluid, the controller may control the DIW to be discharged through the drain lines HD 6  and HD 7 . 
     Residual impurities, HF, or the like may be discharged using the DIW as the flushing fluid. Next, as shown in  FIG. 12C , the controller may control the inert gas to be supplied from the inert gas supply unit  613  through the flushing fluid supply line SS  616  as the flushing fluid and be discharged through the drain lines HD 2  and HD 3 . 
     Residual impurities, DIW, or the like may be discharged by pressure of the inert gas, and at the same time, any residual DIW may be removed by evaporation. 
     Furthermore, through a process similar to that of  FIGS. 11A and 11B , the supply of processing liquid to the sampling line  473  which measures a silica concentration by sampling the processing liquid supplied to the substrate processing apparatus may be stopped, and the drain line HD 8  may be opened to discharge the residual processing liquid. Then, the flushing fluid supply line SS may be opened to flush the selected section including the silica densitometer  475  of the sampling line  473 , and the flushing fluid used to perform flushing may be discharged by opening the drain line 
     Through such a flushing process, solid precipitates, impurities, or the like may be removed from the solid precipitation regions of the main supply unit  470 . In addition, the flushing fluids may also be completely removed using the inert gas, thereby enabling supplying of a high-quality processing solution immediately after flushing. 
       FIGS. 13 and 14  show an embodiment in which flushing of a solid precipitation region of a processing liquid regeneration unit of a processing liquid supply apparatus is performed according to the present disclosure. 
     The processing liquid regeneration unit  560  is the first processing liquid regeneration unit  560  disposed in the processing liquid recycling unit  500  of  FIG. 6 . The first regeneration tank  570  and the selected section of the first regeneration circulation line  561  may be set as solid precipitation regions, and flushing may be performed on the regions. 
     The controller stops the supply of processing liquid from the processing liquid regeneration unit  560  and discharges the processing liquid remaining in the first adjusting tank  570  and the first adjusting circulation line  561  through the drain lines RD 1  and RD 2  as shown in  FIG. 13A . At this time, a four-way valve may be used as the flushing control valves  673   a  and  675   a  of the flushing control system so that the valves may be controlled to circulate the processing liquid of the first regeneration tank  570  and the first regeneration circulation line  561  and discharge the processing liquid through the drain lines RD 1  and RD 2 . 
     The drain lines RD 1  and RD 2  may be combined through the manifold box  691  of the flushing discharge system  690 . The discharged processing liquid may be stored in the buffer tank  695 , subjected to predetermined processing, and discharged to the outside. 
     When the processing liquid remaining in the solid precipitation regions of the first processing liquid regeneration unit  560  gets discharged, as shown in  FIG. 13B , the controller may control the flushing control valve  671   a  disposed at the input end of the first regeneration tank  570  of the first regeneration circulation line  561  to supply the DIW as the flushing fluid to the solid precipitation regions of the first processing liquid regeneration unit  560 . At this time, since a large amount of DIW needs to be supplied to the first regeneration tank  570  of the first processing liquid regeneration unit  560  and the like, the DIW may be supplied through the flushing fluid supply line BS  667  to enable supplying of a large amount of the flushing fluid. 
     In addition, the controller may supply the DIW as the flushing fluid to the first regeneration tank  570  and the first regeneration circulation line  561 , circulate the flushing fluid, and control the flushing control valves  673   a  and  675   a  to discharge the flushing fluid through the drain lines RD 1  and RD 2 . 
     By performing comprehensive flushing of the first regeneration tank  570  and the first regeneration circulation line  561  with the DIW as the flushing fluid, solid precipitates such as silica and impurities may be primarily removed. 
     Next, the controller may control flushing of solid precipitation regions where solid precipitates such as silica may easily be generated. Since accumulation of solid precipitates and impurities may be concentrated near the drain lines for discharging the processing liquid or flushing fluid, intensive flushing may be performed on these solid precipitation regions. 
     In this regard, as shown in  FIG. 14A , the controller may control supplying of the flushing fluid containing HF from the HF supply unit  662  to the flushing control valves  673   a  and  675   a  disposed at the front and rear ends of the regeneration line pump  592 , respectively, through the flushing fluid supply line SS  666 . In some embodiments, an aqueous HF solution whose concentration of HF is adjusted considering the precipitates, impurities, or the like to be removed may be supplied as the flushing fluid. 
     In addition, the controller may perform intensive flushing near the drain lines by controlling the flushing fluid containing HF to be supplied and at the same time, be discharged through the drain lines RD 1  and RD 2 . 
     HF or the like remaining in the corresponding region after flushing with the flushing fluid containing HF affects supplying of a processing liquid thereafter. Therefore, as shown in  FIG. 14B , the controller may control the DIW to be supplied from the DIW supply unit  661  through the flushing fluid supply line SS  666  as the flushing fluid. In addition, while supplying the DIW as the flushing fluid, the controller may control the DIW to be discharged through the drain lines RD 1  and RD 2 . 
     Residual impurities, HF, or the like may be discharged using the DIW as the flushing fluid. 
     Next, as shown in  FIG. 14C , the controller may control the inert gas to be supplied from the inert gas supply unit  663  through the flushing fluid supply line SS  666  as the flushing fluid and be discharged through the drain lines RD 1  and RD 2 . 
     Residual impurities, DIW, or the like may be discharged by pressure of the inert gas, and at the same time, any residual DIW may be removed by evaporation. 
     Through such a flushing process, solid precipitates, impurities, or the like may be removed from the solid precipitation regions of the first processing liquid regeneration unit  560 . In addition, the flushing fluids may also be completely removed using the inert gas, thereby enabling supplying of a high-quality processing solution immediately after flushing. 
       FIGS. 15A to 15C  shows an embodiment in which flushing of a solid precipitation region of a recovery unit of a processing liquid supply apparatus is performed according to the present disclosure. 
     The recovery unit  510  of  FIGS. 15A to 15C  is the recovery unit  510  disposed in the processing liquid recycling unit  500  of  FIG. 6 . A selected section such as the recovery tank  530  of the recovery unit  510  may be set a solid precipitation region, and flushing may be performed on the region. 
     The controller stops the recovery and supply of processing liquid by the recovery unit  510 , controls the flushing control valve  665  to discharge the processing liquid supplied from the substrate processing apparatus  10  directly through the drain line RD 5 , and controls the flushing control valve  687  to discharge the processing liquid remaining in the recovery tank  530  through the drain line RD 6 . 
     When the processing liquid remaining in the solid precipitation regions of the recovery unit  510  gets discharged, as shown in  FIG. 12B , the controller may control the flushing control valve  681  disposed at the input end of the recovery tank  530  to supply the DIW as the flushing fluid to the recovery tank  530  of the recovery unit  510 . At this time, since a large amount of DIW needs to be supplied to the recovery tank  530  and the like, DIW may be supplied through the flushing fluid supply line BS  667  to enable supplying of a large amount of flushing fluid. 
     In addition, while supplying the DIW as the flushing fluid to the recovery tank  530 , the controller may control the flushing control valve  687  to discharge the DIW through the drain line RD 6 . 
     By flushing the recovery tank  530  and the like with the DIW as the flushing fluid, solid precipitates such as silica, impurities, and the like remaining in the recovery tank  530  and the like may be removed. 
     Next, as shown in  FIG. 15C , the controller may control the inert gas to be supplied from the inert gas supply unit  663  through the flushing fluid supply line BS  667  as the flushing fluid, go through the recovery tank  530  and the like, and be discharged through the drain line RD 6 . 
     Residual impurities, DIW, or the like may be discharged by pressure of the inert gas, and at the same time, any residual DIW may be removed by evaporation. 
     Through such a flushing process, solid precipitates, impurities, or the like may be removed from the solid precipitation regions of the recovery unit  510 . In addition, the flushing fluids may also be completely removed using the inert gas, thereby enabling supplying of a high-quality processing solution immediately after flushing. 
     According to the present disclosure as described above, solid precipitates such as silica may be effectively removed from the processing liquid supply apparatus through the flushing process, which may be immediately followed by supplying of the processing liquid. As a result, the present disclosure enables effective maintenance of process yield. 
     In particular, the present disclosure enables removal of precipitated solids, such as silica, by intensively flushing a solid precipitation region of the processing liquid supply apparatus from which silica may easily be precipitated. 
     Although the above description of the present disclosure has been provided for illustrative purposes, those skilled in the art will appreciate that various modifications, additions, and substitutions are possible, without departing from essential characteristics of the disclosure. Therefore, embodiments of the present disclosure are not intended to limit the technical spirit of the disclosure but rather to describe the technical spirit of the disclosure, and the scope of the disclosure is not to be limited by the above embodiments. The scope of the present disclosure is defined only by the accompanying claims and the equivalents thereof