Patent ID: 12207362

DETAILED DESCRIPTION

Hereinafter, an exemplary embodiment of the present invention will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. However, the present invention can be variously implemented and is not limited to the following exemplary embodiments. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein is omitted to avoid making the subject matter of the present invention unclear. In addition, the same reference numerals are used throughout the drawings for parts having similar functions and actions.

Unless explicitly described to the contrary, the term of “including” any component will be understood to imply the inclusion of stated elements but not the exclusion of any other elements. It will be appreciated that terms “including” and “having” are intended to designate the existence of characteristics, numbers, steps, operations, constituent elements, and components described in the specification or a combination thereof, and do not exclude a possibility of the existence or addition of one or more other characteristics, numbers, steps, operations, constituent elements, and components, or a combination thereof in advance.

Singular expressions used herein include plurals expressions unless they have definitely opposite meanings in the context. Accordingly, shapes, sizes, and the like of the elements in the drawing may be exaggerated for clearer description.

Terms, such as first and second, are used for describing various constituent elements, but the constituent elements are not limited by the terms. The terms are used only to discriminate one constituent element from another constituent element. For example, without departing from the scope of the invention, a first constituent element may be named as a second constituent element, and similarly a second constituent element may be named as a first constituent element.

The “unit” used herein may refer a hardware component such as software, FPGA or ASIC, as a unit for processing at least one function or operation. However, the “unit” is not a meaning limited to software or hardware. The “unit” may be configured to be on an addressable storage medium and may be configured to play back one or more processors.

As one example, the “unit” includes components such as software components, object oriented software components, class components, and task components, processes, functions, attributes, procedures, subroutines, segments of a program code, drivers, firmware, microcodes, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided by the component and the ‘unit’ may be separately performed by a plurality of components and ‘units’, or may be integrated with other additional components.

Hereinafter, an exemplary embodiment of the present invention will be described in more detail with reference to the accompanying drawings. The exemplary embodiment of the present invention can be modified in various forms, and it should not be construed that the scope of the present invention is limited to exemplary embodiments described below. The exemplary embodiments will be provided to more completely describe the present invention to those skilled in the art. Therefore, shapes, and the like of components in the drawings will be exaggerated to emphasize a more clear description.

FIGS.1A and1Bare diagrams illustrating a schematic configuration of a chamber according to an exemplary embodiment of the present invention.

As illustrated inFIGS.1A and1B, a plasma chamber100may include electrodes110aand110bto which RF signals are applied. The electrodes110aand110bmay transmit electrical energy to the chamber so that gas to be introduced into the chamber is ionized and changed into a plasma state. The electrodes110aand110billustrated inFIG.1Aillustrates an example of a capacitively coupled plasma (CCP) source disposed so that two electrode plates in the chamber face each other. The CCP source may transmit electric energy to electrons of the gas introduced into the chamber using a capacitively electric field. The CCP source may have a form in which an RF power supply is connected to two electrode plates, but the RF power supply may also be connected only to the upper electrode plate of the two electrode plates according to an exemplary embodiment. An electrode110cillustrated inFIG.1Billustrates an example of an inductively coupled plasma (ICP) source consisting of inductive coils wound outside the chamber100. Since the plasma generation device is separately coupled to the upper portion of the chamber, the ICP source may change the gas introduced in the chamber into a plasma state and provide the plasma to the chamber in a downstream method.

FIG.2is a diagram illustrating a configuration of a substrate treating apparatus according to an exemplary embodiment of the present invention.

Referring toFIG.2, the substrate treating apparatus10processes a substrate S using plasma. For example, the substrate treating apparatus10may perform an etching process for the substrate S. The substrate treating apparatus10may include a chamber100, a substrate support unit200, a plasma generation unit300, a gas supply unit400, and a baffle unit500.

The chamber100may provide a treating space in which a substrate treating process is performed therein. The chamber100may have a treating space therein and may be provided in a closed shape. The chamber100may be provided with a metallic material. The chamber100may be provided with an aluminum material. The chamber100may be grounded. An exhaust hole102may be formed in the bottom surface of the chamber100. The exhaust hole102may be connected with an exhaust line151. Reaction by-products generated in the processing process and gas left in the inner space of the chamber may be discharged to the outside via an exhaust line151. The inside of the chamber100may be decompressed in a predetermined pressure by the exhaust process.

According to an example, a liner130may be provided in the chamber100. A liner130may have a cylindrical shape with opened upper and lower surfaces. The liner130may be provided to be in contact with the inner surface of the chamber100. The liner130protects the inner wall of the chamber100to prevent the inner wall of the chamber100from being damaged by arc discharge. Further, impurities generated during the substrate treating process may be prevented from being deposited on the inner side wall of the chamber100.

The substrate support unit200may be located inside the chamber100. The substrate support unit200may support the substrate S. The substrate support unit200may include an electrostatic chuck210for adsorbing the substrate S using an electrostatic force. Unlike this, the substrate support unit200may support the substrate S in various methods such as mechanical clamping. Hereinafter, the substrate support unit200including the electrostatic chuck210will be described.

The substrate support unit200may include an electrostatic chuck210, a lower cover250, and a plate270. The substrate support unit200may be spaced apart from the bottom surface of the chamber100inside the chamber100.

The electrostatic chuck210may include a dielectric plate220, a body230, and a focusing ring240. The electrostatic chuck210may support the substrate S. The dielectric plate220may be located at the upper end of the electrostatic chuck210. The dielectric plate220may be provided as a disk-shaped dielectric substance. The substrate S may be placed on the upper surface of the dielectric plate220. The upper surface of the dielectric plate220may have a radius smaller than the substrate S. Therefore, an edge region of the substrate S may be located outside the dielectric plate220.

The dielectric plate220may include a first electrode223, a heater225and a first supply flow channel221therein. The first supply flow channel221may be provided on a bottom surface from the upper surface of the dielectric plate210. A plurality of first supply flow channels221may be spaced apart from each other, and may be provided as a passage to which the heat transfer medium is supplied to the lower surface of the substrate S.

The first electrode223may be electrically connected to a first power supply223a. The first power supply223amay include a DC power supply. A switch223bmay be provided between the first electrode223and the first power supply223a. The first electrode223may be electrically connected to the first power supply223aby ON/OFF of the switch223b. When the switch223bis turned on, a direct current may be applied to the first electrode223. The electrostatic force is applied between the first electrode223and the substrate S by the current applied to the first electrode223, and the substrate S may be adsorbed to the dielectric plate220by the electrostatic force. The heater225may be located in the lower portion of the first electrode223. The heater225may be electrically connected to a second power supply225a. The heater225may generate heat by resisting the current applied to the second power supply225a. The generated heat may be transmitted to the substrate S through the dielectric plate220. The substrate S may be maintained at a predetermined temperature by the heat generated in the heater225. The heater225may include a spiral coil.

The body230may be located at a lower portion of the dielectric plate220. The lower surface of the dielectric plate220and the upper surface of the body230may adhere to each other by an adhesive236. The body230may be provided with an aluminum material. The upper surface of the body230may be stepped so that a central region is higher than an edge region. The central region of the upper surface of the body230has an area corresponding to the lower surface of the dielectric plate220and may adhere to the lower surface of the dielectric plate220. The body230may be formed with a first circulation flow channel231, a second circulation flow channel232and a second supply flow channel233therein.

The first circulation flow channel231may be provided as a passage for circulating a heat transfer medium. The first circulation flow channel231may be formed in a spiral shape inside the body230. Alternatively, the first circulation flow channel231may be disposed so that ring-shaped flow channels having different radii have the same center. The respective first circulation flow channels231may communicate with each other. The first circulation flow channels231may be formed at the same height.

The second circulation flow channel232may be provided as a passage for circulating a cooling fluid. The second circulation flow channel232may be formed in a spiral shape inside the body230. Alternatively, the second circulation flow channel232may be disposed so that ring-shaped flow channels having different radii have the same center. The respective second circulation flow channels232may communicate with each other. The second circulation flow channel232may have a cross-sectional area greater than the first circulation flow channel231. The second circulation flow channels232may be formed at the same height. The second circulation flow channel232may be located below the first circulation flow channel231.

The second supply flow channel233extends upward from the first circulation flow channel231and may be provided as the upper surface of the body230. The second supply flow channels243are provided in the number corresponding to the first supply flow channels221, and may connect the first circulation flow channel231and the first supply flow channel221to each other.

The first circulation flow channel231may be connected to a heat transfer medium storage unit231avia a heat transfer medium supply line231b. A heat transfer medium may be stored in the heat transfer medium storage unit231a. The heat transfer medium may include inert gas. According to the exemplary embodiment, the heat transfer medium may include helium (He) gas. The helium gas is supplied to the first circulation flow channel231through the supply line231b, and may be supplied to the lower surface of the substrate S sequentially through the second supply flow channel233and the first supply flow channel221. The helium gas may serve as a medium for transmitting the heat transmitted to the substrate S to the electrostatic chuck210in the plasma.

The second circulation flow channel232may be connected to a cooling fluid storage unit232avia a cooling fluid supply line232c. A cooling fluid may be stored in the cooling fluid storage unit232a. A cooler232bmay be provided in the cooling fluid storage unit232a. The cooler232bmay cool the cooling fluid to a predetermined temperature. Unlike this, the cooler232bmay be provided on the cooling fluid supply line232c. The cooling fluid supplied to the second circulation flow channel232through the cooling fluid supply line232cmay circulate along the second circulation flow channel232and cool the body230. The body230may cool the dielectric plate220and the substrate S together while cooling to maintain the substrate S to a predetermined temperature.

The body230may include a metal plate. According to an exemplary embodiment, the entire body230may be provided as a metal plate. The body230may be electrically connected to a third power supply235a. The third power supply235amay be provided as a high-frequency power supply for generating high-frequency power. The high-frequency power supply may include an RF power supply. The body230may receive the high-frequency power from the third power supply235a. As a result, the body230may function as an electrode, that is, a lower electrode.

A ring member240may be disposed in an edge region of the electrostatic chuck210. The ring member240has an annular ring shape and may be disposed along the circumference of the dielectric plate220. In particular, the ring member240may consist of a plurality of rings including a focus ring. Particularly, the upper surface of the ring member240may be stepped so that an outer portion240ais higher than an inner portion240b. The inner portion240bof the upper surface of the ring member240may be located at the same height as the upper surface of the dielectric plate220. The inner portion240bof the upper surface of the ring member240may support the edge region of the substrate S located outside the dielectric plate220. The outer portion240aof the ring member240may be provided to surround the edge region of the substrate S. The ring member240may control an electromagnetic field so that the density of the plasma is uniformly distributed in the entire region of the substrate S. As a result, the plasma may be uniformly formed across the entire region of the substrate S so that each region of the substrate S may be uniformly etched.

The lower cover250may be located at the lower end of the substrate support unit200. The lower cover250may be located to be spaced apart upward from the bottom surface of the chamber100. The lower cover250may be formed with a space255having an opened upper surface therein. The outer radius of the lower cover250may be provided with the same length as the outer radius of the body230. In the inner space255of the lower cover250, a lift pin module (not illustrated) or the like that moves the substrate S to be transferred from an external transfer member to the electrostatic chuck210may be located. The lift pin modules (not illustrated) may be located to be spaced apart from the lower cover250at predetermined intervals. The lower surface of the lower cover250may be provided with a metallic material. The inner space255of the lower cover250may be provided with air. Since the air has a dielectric constant lower than an insulator, the air may serve to reduce the electromagnetic field inside the substrate support unit200.

The lower cover250may have a connection member253. The connection member253may connect an outer surface of the lower cover250and an inner wall of the chamber100to each other. A plurality of connection members253may be provided on the outer surface of the lower cover250with a plurality of intervals. The connection member253may support the substrate support unit200inside the chamber100. In addition, the connection member253is connected to the inner wall of the chamber100so that the lower cover250is electrically grounded. A first power supply line223cconnected with the first power supply223a, a second power supply line225cconnected with the second power supply225a, a third power supply line235cconnected with the third power supply235a, a heat transfer medium supply line231bconnected to the heat transfer medium storage unit231a, a cooling fluid supply line232cconnected with the cooling fluid storage unit232a, and the like may extend to the inside of the lower cover250through the inner space255of the connection member253.

The plate270may be located between the electrostatic chuck210and the lower cover250. The plate270may cover the upper surface of the lower cover250. The plate270may be provided in a cross-sectional area corresponding to the body230. The plate270may include an insulator. According to an exemplary embodiment, one or a plurality of plate(s)270may be provided. The plate270may serve to increase an electrical distance between the body230and the lower cover250.

The plasma generation unit300may excite process gas in the chamber100into a plasma state. The plasma generation unit300may use a capacitively coupled plasma type plasma source. When the CCP type plasma source is used, the upper electrode330and the lower electrode230, that is, the body, may be included in the chamber100. The upper electrode330and the lower electrode230may be disposed up and down in parallel with each other with a treating space interposed therebetween. The upper electrode330as well as the lower electrode230may also receive energy for generating the plasma by receiving the RF signal by the RF power supply310, and the number of RF signals applied to each electrode is not limited to one as illustrated in the drawing. An electric field is formed in a space between the both electrodes, and the process gas supplied to the space may be excited into the plasma state. A substrate treating process is performed using this plasma. The CCP type described herein has been described, but is not limited thereto, and the plasma generation unit300may be configured as an inductively coupled plasma (ICP) type.

The plasma generation unit300may be provided with a gas dispersion plate. Although not illustrated in the drawing, the gas dispersion plate may be disposed to be spaced apart from the upper surface of the chamber100at a predetermined distance. The gas dispersion plate may be fixed by a support unit formed on the edge of the upper surface of the chamber100. The gas dispersion plate may be provided in a plate shape with a constant thickness. The lower surface of the gas dispersion plate may be polarized to prevent the arc generated by the plasma. The cross-sectional area of the gas dispersion plate may be provided to be the same as the cross-sectional area of the substrate support unit200. The gas dispersion plate includes a plurality of injection holes. The injection holes may penetrate through the upper surface and the lower surface of the gas dispersion plate in a vertical direction. The gas dispersion plate310may include a metallic material. The gas dispersion plate310of the metallic material may perform a function as the upper electrode.

The gas supply unit400may supply process gas into the chamber100. The gas supply unit400may include a gas supply nozzle410, a gas supply line420, and a gas storage unit430. The gas supply unit410may be provided at the center of the upper surface of the chamber100. An injection port may be formed on the lower surface of the gas supply nozzle410. The injection port may supply process gas into the chamber100. The gas supply line420may connect the gas supply nozzle410and the gas storage unit430to each other. The gas supply line420may supply the process gas stored in the gas storage unit430to the gas supply nozzle410. The gas supply line420may be provided with a valve421. The valve421may open and close the gas supply line420and adjust the flow rate of the process gas supplied through the gas supply line420.

The baffle unit500may be located between the inner wall of the chamber100and the substrate support unit200. The baffle510may be provided in an annular ring shape. A plurality of through holes511may be formed in the baffle510. The process gas provided in the chamber100may be exhausted to the exhaust hole102through the through holes511of the baffle510. The flow of the process gas may be controlled according to the shape of the baffle510and the shapes of the through holes511.

FIG.3is a diagram illustrating an exploded perspective view of the support unit200according to an exemplary embodiment of the present invention.

In the support unit200according toFIG.3, the description of the components described in the support unit200ofFIG.2described above will be omitted. According toFIG.3, the support unit200according to the present invention may further include a control board290, a connection board280, and a connection electrode unit227.

The control board290according to the present invention may control a first switch231, a second switch232and a third switch233connected to the heater230in a matrix structure included in the support unit200according to the present invention. In the exemplary embodiment, the control board290according to the present invention may include a control unit to be described below. The control board290may generate control signals for controlling the first switch231, the second switch232and the third switch233connected to the heater230in the matrix structure included in the support unit200according to the present invention and apply the control signals. The control signal may be a digital signal, for example, an on/off signal. The control board290may be implemented as a computer or a device similar thereto using hardware, software, or a combination thereof.

In the hardware, the control board290may be implemented as application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, micro-controllers, microprocessors, or electronic devices for performing control functions similar thereto.

In the software, the control board290may be implemented as a software code or a software application according to one or a plurality of programming languages. The software may be executed by a controller implemented in hardware. In addition, the software may also be transmitted and provided as the hardware configuration described above from an external device such as a server or the like.

In the exemplary embodiment, the connection board280may be disposed between the heater225and the control board290. In the exemplary embodiment, the connection electrode unit227may electrically connect the heater225, the control board290, and the connection board280to each other.

The support unit200according to the present invention may include a plurality of heaters225disposed in a matrix form in the support unit200to heat the substrate, a power supply unit225asupplying the power to the plurality of heaters225, and switches231,232, and233connected to rows and columns of a heater matrix. The support unit200according to the present invention may further include a control unit290for controlling the on/off of the switches231,232, and233connected to rows and columns of the heater matrix.

Hereinafter, a connection structure and a control method of the heater225matrix according to the present invention will be described in detail through a circuit diagram.

FIG.4is a diagram illustrating a structure of the heater225matrix according to an exemplary embodiment of the present invention.

Referring toFIG.4, the heater225matrix according to the present invention may include a plurality of heaters225′,225″,225′″,225″″ . . . arranged in a matrix structure and switches2251,2252, and2253connected to the plurality of heaters225, respectively. In the exemplary embodiment of the present invention, the heater matrix according to the present invention may be provided to be arranged based on rows and columns. The heater matrix has a plurality of rows and a plurality of rows, and the heaters225′,225″,225′″,225″″ . . . may be connected to intersections thereof.

In the exemplary embodiment of the present invention, the support unit200of the present invention may include a first switch2251and a second switch2252connected to rows of the matrix and a third switch2253connected to a column of the matrix.

Referring toFIG.4, each row of the heater225matrix may be connected with the first switch2251capable of controlling a current applied to the row of the matrix. Each row of the heater225matrix may be connected with the second switch2252connected in parallel with the first switch2251capable of controlling the current applied to the row of the matrix.

The first switch2251and the second switch2252are connected to each row of the heater225matrix. In the exemplary embodiment, when four rows are provided to the heater225matrix, total four first switches2251a,2251b,2251c, and2251d, and four second switches2252a,2252b,2252c, and2252dmay be provided. In the exemplary embodiment, when n rows are provided to the heater225matrix, total n first switches2251a, . . . ,2251nand n second switches2252a, . . . ,2252nmay be provided. That is, in the exemplary embodiment of the present invention, the first switch2251and the second switch2252may be connected for each row of the matrix, respectively.

In the exemplary embodiment, one end of the second switch2252is connected in parallel with one end of the first switch2251, and the other end of the second switch2252may be connected to the ground.

The support unit of the present invention may further include a third switch2253connected to each column of the matrix. The third switches2253may be provided in the same number as the number of columns of the matrix.

Although not illustrated inFIG.4, the support unit200according to the present invention may further include a control unit290for controlling the on/off of the first switch2251, the second switch2252and the third switch2253. The control unit according to the present invention may connect the first switch2251of the row connected to the target heater225and the third switch2253of the column connected to the target heater225, in order to measure the current of the target heater225included in the matrix. The control unit according to the present invention may control the second switches2252of other rows which are not connected with the target heater225to be connected. Thus, there is an effect of being configured so that the current flows only in the target heater225, and as a result, there is an effect of enabling the accurate current measurement in the target heater225.

In more detail, a control method of the control unit will be described below with reference toFIG.5.

A target heater225′ may be set among the plurality of heaters225arranged in the matrix form. The control unit according to the present invention may control a first switch2251aof a row connected with the target heater225′ to be turned on. In addition the control unit according to the present invention may control all second switches2252b,2252c, and2252dconnected to the remaining rows other than the row connected with the target heater225′ to be turned on.

In addition, the control unit according to the present invention may control a third switch2253aof a row connected with the target heater225′ to be turned on.

That is, the control unit according to the present invention may control the first switch2251aof the row connected with the target heater225′ to be turned on, control the second switches2252b,2252c, and2252dconnected to the remaining rows other than the row connected with the target heater225′ to be turned on, and control the third switch2253aof the row connected with the target heater225′ to be turned on, thereby controlling the current to flow only through the target heater225′ among the plurality of heaters. That is, the control unit according to the present invention may control any one of the first switch2251aand the second switch2252aconnected for each of the plurality of rows included in the heater matrix to be connected, and the control unit may control only any one of the first switches2251a,2251b,2251c, and2251dcorresponding to the number of the plurality of rows to be connected and control the second switches2252in the remaining rows to be connected. As a result, the control unit may control the current to flow through only the target heater225′ among the plurality of heaters, and measure a current value which does not pass through the remaining heaters except for the target heater225′ among the plurality of heaters.

In the exemplary embodiment ofFIGS.4and5, in the process of measuring the current, a pair of the first switch2251and the second switch2252connected to each row of the heater225matrix may be provided by the number of rows in the heater225matrix. In the exemplary embodiment ofFIGS.4and5, four pairs of first switches2251and second switches2252may be provided, and among four first switches2251and four second switches2252included in four pairs, one first switch2251amay be turned on and three second switches2252b,2252c, and2252dmay be turned on.

In the present invention, the second switches2252b,2252c, and2252dare connected to the heaters in the remaining rows that are not connected with the target heater225′, so that the current flowing in the remaining rows may be controlled to be connected as the ground.

In the exemplary embodiment, the first switch2251may be a power supplying switch. In the exemplary embodiment, the second switch2252may be a power blocking switch. In the exemplary embodiment, the third switch2253may be a power returning switch.

In the case of using the structure of heater225according to the present invention, since the current flows in addition to the target heater225′, but the current flowing to the lower switch corresponds to the current passing through only the target heater225′, the heat value and temperature of the desired target heater225′ may be accurately calculated using the same.

FIG.6illustrates an equivalent circuit for describing measuring the current of the target heater225′ according to an exemplary embodiment of the present invention.

FIG.6illustrates a circuit structure of the matrix heater according toFIG.5as an equivalent circuit. As illustrated inFIG.5, when one target heater225′ is set, the current flowing in the target heater225′ shown on the leftmost side is supplied only to cells of the desired target heater225′ to calculate the temperature through the resistance of the target heater225′ by the measurement of the voltage and current. When the resistance in each heater is assumed as R, it is as follows.

As a result, there is an effect of enabling precise temperature control by making a configuration of a feedback loop that could not be applied in related art.

Through the equivalent circuit, the resistance may be calculated by the following equations.

RP=R3=13⁢R⁢RS=R+R3=43⁢R⁢RPS=RS3=4⁢R33=49⁢R⁢Rtot=11R+1RPS=413⁢R

FIG.7is a flowchart illustrating a temperature control method according to an exemplary embodiment of the present invention.

According to the temperature control method according to the present invention, the current flowing through the target heater225′ is measured and as a result, the resistance value may be calculated. In addition, as a result, the temperatures in the region of the target heater225′ may be calculated and compared to each other to adjust the output power at the target heater225′.

That is, in the temperature control method according to the present invention, the target current measurement and the resistance value calculation at the target heater225′ may be performed. This indicates that the target current may be controlled to be supplied to only the target heater225′ through the switch control in the switch structure according to the present invention, thereby calculating the temperature and adjusting the output power of the target heater225′.

The switch control of the control unit may be performed to connect the first switch2251of the row connected with the target heater225′ and connect the third switch2253of the column connected with the target heater225′, and performed to turn off the second switch2252connected to the target heater225′ and turn on the second switches2252connected to the remaining rows other than the target heater225′. As a result, the current may be controlled to flow in the region of the selected target heater225′.

According to a temperature control method according to a first exemplary embodiment of the present invention, a region of a heater to be controlled as a target is selected as the target heater225′, switches are controlled so that the current flows only in the region of the selected heater225′, and then a current value flowing in the region of the selected heater225′ is measured, thereby checking the temperature of the region of the selected heater225′ and then controlling the temperature of the region of the selected heater225′.

According to a temperature control method according to a second exemplary embodiment of the present invention, a heater region to control the temperature is set as the target heater225′, target power of the target heater225′ is set, and then switches are controlled so that the current flows only in the region of the selected heater225′, and a current value flowing in the region of the selected heater225′ is measured, thereby checking the temperature of the region of the selected heater225′ and then checking whether to match the temperature of the region of the heater225′ with the target power. At this time, the temperature control method may include controlling the temperature of the region of the heater225′, when the temperature of the region of the heater225′ is not matched.

It is to be understood that the exemplary embodiments are presented to assist in understanding of the present invention, and the scope of the present invention is not limited, and various modified exemplary embodiments thereof are included in the scope of the present invention. The drawings provided in the present invention are only illustrative of an optimal exemplary embodiment of the present invention. The technical protection scope of the present invention should be determined by the technical idea of the appended claims, and it should be understood that the technical protective scope of the present invention is not limited to the literary disclosure itself in the appended claims, but the technical value is substantially affected on the equivalent scope of the invention.