Substrate processing apparatus and substrate processing method, and electrostatic chuck manufacturing method

Abstract

Disclosed is a substrate processing apparatus and a substrate processing method, and an electrostatic chuck manufacturing method. Provided is an electrostatic chuck including: a chuck member that supports a substrate and has at least one pin hole that penetrates in a vertical direction, and a lift pin that is housed in the pin hole so as to be able to be raised and lowered; and an expansion member that is provided to an inner periphery of the pin hole and is able to expand, and has an inner peripheral surface that comes into close contact with an outer peripheral surface of the lift pin housed in the pin hole when the expansion member expands, and the diameter of the pin hole is changed by the expansion member.

Description

Technical Field

[0001] The present invention relates to a substrate processing apparatus, a substrate processing method, and a method for manufacturing the same, which includes an electrostatic chuck for processing substrates such as semiconductor wafers. Background Technology

[0002] Recently, plasma processing equipment has been widely used in the manufacturing process of semiconductor devices, specifically in the process of forming or etching films on semiconductor substrates.

[0003] The plasma processing equipment includes a process chamber having space for processing a semiconductor substrate and a substrate support device disposed inside the process chamber to support the semiconductor substrate.

[0004] As an example of a substrate support device, there is an electrostatic chuck. A typical electrostatic chuck includes a base plate made of aluminum, a ceramic positioner disposed on the upper side of the base plate, and an internal electrode disposed inside the ceramic positioner. A power source for generating electrostatic force is connected to the internal electrode, and the semiconductor substrate is attracted and fixed to the electrostatic chuck by electrostatic force.

[0005] The semiconductor substrate, located on an electrostatic chuck, is heated by plasma gas. Cooling gas for regulating the temperature of the semiconductor substrate is supplied to the back side of the substrate. Helium (He) gas is primarily used as the cooling gas, and it is supplied to the back side of the semiconductor substrate through cooling gas supply holes formed in the base plate and the ceramic positioner.

[0006] In addition, there is a pin hole that runs through the base plate and the ceramic locator. The lifting pin moves up and down along the pin hole, which helps to disassemble the substrate.

[0007] As semiconductors become increasingly miniaturized, the radio frequency (RF) power used to generate plasma gradually increases. Consequently, the occurrence of discharge phenomena (e.g., arcing) within cooling gas supply holes and pin holes has become a serious problem. These discharge phenomena can damage the substrate support and the substrate itself. In particular, this problem occurs more frequently in pin holes where the diameter is larger than that of the cooling gas supply holes.

[0008] For example, when the substrate is held in place by the electrostatic chuck, there is a high probability that helium gas supplied to the cooling gas supply hole will flow into the pin hole. If the substrate temperature locally increases while the helium gas stagnating in the pin hole becomes a high-temperature environment, plasma discharge may occur in the pin hole, damaging both the substrate and the electrostatic chuck. Furthermore, the repeated operation of the lifting pin causes particles to be exposed on the surface of the electrostatic chuck due to the wide diameter of the pin hole, potentially leading to discharge. Plasma may also flow into the lifting pin when it comes into contact with a point of low resistance that is not intentionally designed for this purpose, also potentially causing a discharge. Summary of the Invention

[0009] The present invention aims to provide an electrostatic chuck capable of preventing discharge within a substrate processing apparatus and a method thereof.

[0010] The objectives of this invention are not limited to those described above, and other objectives and advantages of this invention not mentioned may be understood from the following description.

[0011] According to an embodiment of the present invention, an electrostatic chuck can be provided, comprising: a chuck component, a support substrate and at least one pin hole extending in the vertical direction, and a lifting pin being movably accommodated in the pin hole; and an expansion component provided on the inner periphery of the pin hole and capable of expansion, and having an inner peripheral surface that, when expanded, is in close contact with the outer peripheral surface of the lifting pin accommodated in the pin hole.

[0012] In one embodiment, the expansion member may be a piezoelectric element having the inner circumferential surface and expanding according to a power supply.

[0013] Alternatively, the electrostatic chuck may further include: electrodes, which are built into the chuck component and generate electrostatic force.

[0014] Alternatively, the piezoelectric element may be electrically connected to the electrode, and if a power source is applied to the electrode, the piezoelectric element receives the power source from the electrode and expands.

[0015] Alternatively, if the power supply to the electrode is cut off, the piezoelectric element will return to its state before expansion.

[0016] Alternatively, the chuck component may be formed of a dielectric material, and the piezoelectric element may be a material having the same dielectric constant as the chuck component while having a higher volume resistivity compared to the chuck component.

[0017] Alternatively, the chuck component and the piezoelectric element can be combined by sintering.

[0018] Alternatively, the piezoelectric element and the electrode can receive power separately and be controlled independently.

[0019] Alternatively, the pin hole may form a receiving groove at its upper end to accommodate the expansion component.

[0020] According to an embodiment of the present invention, a substrate processing apparatus may be provided, comprising: a process chamber providing a substrate processing space; an electrostatic chuck disposed in the substrate processing space; and a plasma generator for generating plasma in the substrate processing space. The electrostatic chuck may include: a chuck component supporting a substrate and having at least one pin hole extending vertically, and a lifting pin being vertically and elliptically accommodated in the pin hole; and an expansion component provided on the inner periphery of the pin hole and capable of expansion, having an inner peripheral surface that, when expanded, is in close contact with the outer peripheral surface of the lifting pin accommodated in the pin hole, wherein the expansion component is a tubular piezoelectric element that expands according to a power supply.

[0021] Alternatively, the piezoelectric element may be electrically connected to an electrode that generates electrostatic force in the electrostatic chuck. If a power source is applied to the electrode, the piezoelectric element receives the power from the electrode and expands toward the inside of the pin hole.

[0022] Alternatively, if the power supply to the electrode is cut off, the piezoelectric element will return to its original state.

[0023] Alternatively, the piezoelectric element may be connected to a separately controlled power supply.

[0024] Alternatively, the piezoelectric element may have a higher volume resistivity than the chuck component.

[0025] According to an embodiment of the present invention, a substrate processing method is provided, which processes a substrate using an electrostatic chuck, wherein the electrostatic chuck includes: a chuck component that supports the substrate and has at least one pin hole extending in the vertical direction, and a lifting pin is movably accommodated in the pin hole; an electrode built into the chuck component to generate electrostatic force in the chuck component; and a piezoelectric element provided in the inner periphery of the pin hole and capable of expansion, having an inner peripheral surface that, when expanded, is in close contact with the outer peripheral surface of the lifting pin accommodated in the pin hole. Alternatively, the substrate processing method may perform plasma processing in a state where the inner peripheral length of the pin hole decreases as the piezoelectric element expands when a power source is applied to the chuck component and the substrate is clamped.

[0026] Alternatively, if the plasma treatment is completed, when the power supply to the chuck component is cut off and the substrate is released from clamping, the piezoelectric element returns to its state before expansion, and the reduced inner circumference length of the pin hole returns to its length before reduction.

[0027] According to an embodiment of the present invention, an electrostatic chuck manufacturing method is provided, comprising: machining a pin hole for lifting a lifting pin in a manner that penetrates the upper and lower surfaces of a chuck component; inserting an expansion member having an inner circumferential surface that, when expanded, is in close contact with the outer circumferential surface of the lifting pin at the upper end of the pin hole; and fixing the inserted expansion member to the chuck component.

[0028] Alternatively, the expansion component may be a tubular piezoelectric element having a higher volume resistivity than the chuck component and expanding according to the power supply.

[0029] The step of machining the pin hole may include counterboring the upper end of the pin hole in the shape of the expansion member.

[0030] Alternatively, at least one pin hole may be formed in the chuck component.

[0031] According to an embodiment of the present invention, a reverse piezoelectric effect is generated by supplying current to a piezoelectric element suitable for the pin hole. The piezoelectric element expands due to the reverse piezoelectric effect, and the diameter of the pin hole shrinks accordingly, preventing cooling gas from flowing into the pin hole and particles from flowing out of the pin hole, thereby minimizing discharge within the substrate processing apparatus.

[0032] In addition, a piezoelectric element with a higher volume resistivity than the chuck component is used, thereby increasing the resistance around the pin and reducing the possibility of plasma flowing into the pin hole.

[0033] The effects of the present invention are not limited to those described above, but should be understood to include all effects that can be inferred from the structure of the invention as described in the detailed description of the invention or the claims. Attached Figure Description

[0034] Figure 1 A cross-sectional view of a substrate processing apparatus according to an embodiment of the present invention is shown.

[0035] Figure 2 A diagram showing the structure of a pin hole according to an embodiment of the present invention.

[0036] Figure 3 as well as Figure 4 A diagram illustrating the operation of a pin hole according to an embodiment of the present invention is shown.

[0037] Figure 5 A flowchart illustrating a method for manufacturing an electrostatic chuck according to an embodiment of the present invention is shown.

[0038] (Explanation of reference numerals in the attached diagram)

[0039] 200: Electrostatic Chuck

[0040] 210: Chuck components

[0041] 211: Dielectric disk

[0042] 212: Electrode

[0043] 220: Pin hole

[0044] 240: Boost Sales

[0045] 500: Expansion component Detailed Implementation

[0046] The terminology and accompanying drawings used in this specification are for illustrative purposes only, and therefore the invention is not limited to the terminology and drawings. Detailed descriptions of well-known techniques used in the invention that are not closely related to the inventive concept are omitted. The embodiments described in this specification are intended to clearly illustrate the invention to those skilled in the art; therefore, the invention is not limited to the embodiments described in this specification, and should be interpreted as including modifications or variations that do not depart from the inventive concept.

[0047] In embodiments of the present invention, a substrate processing apparatus having an inductively coupled plasma (ICP) source that uses plasma to etch a substrate is described. However, the present invention is not limited thereto, and can be applied to various types of apparatuses that provide lift pins and perform processes on substrates, such as substrate processing apparatuses having capacitively coupled plasma (CCP) sources.

[0048] In addition, in embodiments of the present invention, an electrostatic chuck is exemplified as a substrate support unit. However, the present invention is not limited thereto; when an electrostatic chuck is not necessary, the support unit can support the substrate by mechanical clamping or by vacuum.

[0049] Figure 1 A cross-sectional view of a substrate processing apparatus according to an embodiment of the present invention is shown.

[0050] Reference Figure 1 The substrate processing apparatus 10 uses plasma to process the substrate W. For example, the substrate processing apparatus 10 can perform an etching process on the substrate W. The substrate processing apparatus 10 may include a chamber 100, a substrate support unit 200, a gas supply unit 300, and a plasma source unit 400.

[0051] Chamber 100 provides space for performing plasma processing, and substrate support unit 200 supports substrate W inside chamber 100. Gas supply unit 300 supplies process gas into chamber 100, and plasma source unit 400 provides electromagnetic waves into chamber 100 to generate plasma from the process gas. The structures are described in detail below.

[0052] Chamber 100 includes a chamber body 110 and a cover 120. The top of the chamber body 110 is open, forming an internal space. Vent holes 113 are formed on the bottom wall of the chamber body 110. The vent holes 113 are connected to an exhaust line 117, providing a channel for gases trapped inside the chamber body 110 and reaction byproducts generated during the process to be discharged to the outside. Multiple vent holes 113 may be provided in the edge region of the bottom wall of the chamber body 110.

[0053] The cover 120 is the open top of the sealed chamber body 110. The cover 120 has a radius corresponding to the circumference of the chamber body 110. The cover 120 may be made of a dielectric material. The cover 120 may be made of aluminum. The space surrounded by the cover 120 and the chamber body 110 provides a processing space 130 for performing plasma processing.

[0054] A partition 250 controls the flow of process gas within the chamber 100. The partition 250 is provided in an annular shape and is located between the chamber 100 and the substrate support unit 200. A distribution hole 251 is formed in the partition 250. Process gas retained in the chamber 100 flows through the distribution hole 251 into the exhaust hole 113. The flow of process gas into the exhaust hole 113 can be controlled according to the shape and arrangement of the distribution hole 251.

[0055] The gas supply unit 300 supplies process gas into the chamber 100. The gas supply unit 300 includes a nozzle 310, a gas storage unit 320, and a gas supply line 330.

[0056] Nozzle 310 is mounted on cover 120. Nozzle 310 may be located in the central region of cover 120. Nozzle 310 is connected to gas storage unit 320 via gas supply line 330. Valve 340 is provided on gas supply line 330. Valve 340 opens and closes gas supply line 330 and regulates the supply flow rate of process gas. Process gas stored in gas storage unit 320 is supplied to nozzle 310 via gas supply line 330 and injected into chamber 100 from nozzle 310. Nozzle 310 mainly supplies process gas to the central region of processing space 130. In contrast, gas supply unit 300 may also include nozzles (not shown) mounted on the side wall of chamber body 110. In this case, nozzles supply process gas to the edge region of processing space 130.

[0057] The plasma source unit 400 generates plasma from process gas. The plasma source unit 400 includes an antenna 410, a power supply 420, and an upper cover 430.

[0058] Antenna 410 is provided at the upper part of cavity 100. Antenna 410 may be provided as a spiral coil. Power supply 420 is connected to antenna 410 via a cable and applies high-frequency power to antenna 410. The application of high-frequency power generates electromagnetic waves in antenna 410. The electromagnetic waves form an induced electric field inside cavity 100. Process gas gains the energy required for ionization from the induced electric field to generate plasma. The plasma can be provided to substrate W and used to perform etching processes.

[0059] The substrate support unit 200 is located in the processing space 130 and supports the substrate W. The substrate support unit 200 can fix the substrate W by electrostatic force or by mechanical clamping. Hereinafter, an example is given of an electrostatic chuck in which the substrate support unit 200 fixes the substrate W by electrostatic force.

[0060] The electrostatic chuck 200 includes a chuck component 210, a housing 230, and a lifting pin 240.

[0061] The chuck component 210 uses electrostatic force to attract the substrate W. The chuck component 210 may include a dielectric disk 211, an electrode 212, a heater 213, a focusing ring 214, an insulating disk 215, and a grounding disk 216.

[0062] The dielectric disk 211 is provided in a disk shape. The upper surface of the dielectric disk 211 may have a radius corresponding to or smaller than that of the substrate W. A protrusion 211a may be formed on the upper surface of the dielectric disk 211. The substrate W is placed on the protrusion 211a and spaced apart from the upper surface of the dielectric disk 211 by a certain distance. The dielectric disk 211 may have stepped sides such that the lower region has a larger radius than the upper region. As an example, the dielectric disk 211 may be Al2O3.

[0063] Electrode 212 is embedded inside dielectric disk 211. Electrode 212 is a thin, conductive disk connected to an external power source (not shown) via cable 221. The power applied from the external power source creates an electrostatic force between electrode 212 and substrate W, thus fixing substrate W to the dielectric disk 211. The external power source can be a DC power source.

[0064] A heater 213 is provided inside the dielectric disk 211. The heater 213 can be provided below the electrode 212. The heater 213 is connected to an external power source (not shown) via a cable 222. The heater 213 generates heat by resisting the current applied from the external power source. The generated heat is transferred through the dielectric disk 211 to the substrate W, heating the substrate W to a predetermined temperature. The heater 213 can be provided as a spiral coil, embedded within the dielectric disk 211 at uniform intervals.

[0065] A focusing ring 214 is provided in a ring shape and is arranged circumferentially along the upper region of the dielectric disk 211. The upper surface of the focusing ring 214 may be stepped, such that the inner portion adjacent to the dielectric disk 211 is lower than the outer portion. The inner portion of the upper surface of the focusing ring 214 may be located at the same height as the upper surface of the dielectric disk 211. The focusing ring 214 extends the electromagnetic field forming region so that the substrate is located at the center of the plasma forming region. Thus, plasma can be uniformly formed throughout the entire region of the substrate W.

[0066] An insulating disk 215 is located below and supports the dielectric disk 211. The insulating disk 215 is a disc of a certain thickness and may have a radius corresponding to that of the dielectric disk 211. The insulating disk 215 is made of insulating material. The insulating disk 215 is connected to an external power source (not shown) via a cable 223. A high-frequency current applied to the insulating disk 215 via the cable (223) creates an electromagnetic field between the electrostatic chuck 200 and the cover 120. The electromagnetic field provides energy for generating plasma.

[0067] A cooling flow path 211b can be formed in the insulating disk 215. The cooling flow path 211b is located below the heater 213. The cooling flow path 211b provides a channel for the circulation of cooling fluid. The heat of the cooling fluid is transferred to the dielectric disk 211 and the substrate W, rapidly cooling the heated dielectric disk 211 and the substrate W. The cooling flow path 211b can be formed in a spiral shape. Alternatively, the cooling flow path 211b can be configured as annular flow paths with different radii having the same center. The individual flow paths can be interconnected. Alternatively, the cooling flow path 211b can be formed on the grounding disk 216.

[0068] Grounding plate 216 is located below insulating plate 215. Grounding plate 216 can be a disc with a certain thickness and a radius corresponding to that of insulating plate 215. Grounding plate 216 is grounded. Grounding plate 216 can electrically insulate insulating plate 215 and chamber body 110.

[0069] A pin hole 220 is formed in the chuck component 210. The pin hole 220 is formed on the top of the chuck component 210. Furthermore, the pin hole 220 can vertically penetrate the chuck component 210. The pin hole 220 extends from the top of the dielectric disk 211, sequentially through the dielectric disk 211, the insulating disk 215, and the grounding disk 216 to the bottom of the grounding disk 216.

[0070] Multiple pin holes 220 can be formed. Multiple pin holes 220 can be arranged in the circumferential direction of the dielectric disk 211. For example, three pin holes 220 can be arranged at 120-degree intervals in the circumferential direction of the dielectric disk 211. Alternatively, various numbers of pin holes 220 can be formed, such as four pin holes 220 arranged at 90-degree intervals in the circumferential direction of the dielectric disk 211.

[0071] Furthermore, the pin hole 220 can be formed on the protrusion 211a of the dielectric disk 211. For example, a circular pin hole 220 can be formed in the center of the protrusion 211a, which has a circular planar shape. However, the planar shapes of the protrusion 211a and the pin hole 220 can be configured in various ways. The pin hole 220 can be formed in a portion of the protrusion 211a. For example, six protrusions 211a can be arranged at 60-degree intervals in the circumferential direction of the dielectric disk 211, and three pin holes 220 can be arranged at 30-degree intervals. A receiving groove for accommodating the expansion member 500, which will be described later, can be formed at the upper end of the pin hole 220.

[0072] The housing 230 is located below and supports the grounding plate 216. The housing 230 is a cylinder of a certain height, forming an internal space. The housing 230 may have a radius corresponding to that of the grounding plate 216. Various cables (not shown) and lifting pins 240 are arranged inside the housing 230.

[0073] The lifting pin 240 loads the substrate W onto or unloads the substrate W from the dielectric disk 211 by rising and falling. The lifting pin 240 supports the substrate W.

[0074] Multiple lifting pins 240 are provided and are accommodated within each of the pin holes 220. Here, the diameter of the lifting pin 240 is formed to be smaller than the diameter of the pin hole 220. Specifically, the diameter of the lifting pin 240 can be set to the minimum diameter that prevents the lifting pin 240 from contacting the inner wall of the pin hole 220 when the lifting pin 240 and the pin hole 220 are configured to have the same central axis.

[0075] The lifting pin 240 can be driven in the vertical direction by a drive unit (not shown).

[0076] Reference Figure 2 The pin hole 220 provides a diameter that can be varied.

[0077] An electrostatic chuck 200 according to an embodiment of the present invention may further include an expansion member 500 provided on the inner periphery of the pin hole 220. The expansion member 500 can reversibly expand and recover repeatedly, and is provided to change the size of the inner periphery of the expansion member 500 according to the expansion and recovery. Normally, the size of the inner periphery of the expansion member 500 is slightly larger than the diameter of the lifting pin 240. When expanding, the size of the inner periphery of the expansion member 500 changes to be the same as the diameter of the lifting pin 240 as the expansion member 500 expands inward toward the pin hole 220. Therefore, if the expansion member 500 expands, the inner peripheral surface of the expansion member 500 is in close contact with the outer peripheral surface of the lifting pin 240, and the diameter of the pin hole 220 with the expansion member 500 becomes smaller than the normal diameter.

[0078] As an example, if a power source is supplied, the expansion member 500 can be an expanding piezoelectric element. Specifically, a tubular piezoelectric element 500 can be inserted into the dielectric disk 211 at the upper end of the pin hole 220. Here, the inner diameter of the tubular piezoelectric element 500 in the absence of flowing current is formed to be the same as the diameter of the existing pin hole 220. In this case, it is preferable that the piezoelectric element 500 is embedded in the dielectric disk 211 and electrically connected to the electrode 212 that generates electrostatic force in the chuck member 210.

[0079] The piezoelectric effect is a phenomenon where, when pressure is applied, the ionic crystal structure of a substance changes, the centers of positive and negative ions shift and lose symmetry, and a dipole moment is generated, resulting in polarization throughout the substance. As a result, mechanical energy is converted into electrical energy. A piezoelectric element is a component that exhibits this piezoelectric effect. The piezoelectric effect is reversible; therefore, if electrical energy is applied to a piezoelectric element, the inverse piezoelectric effect occurs, producing mechanical deformation.

[0080] Figure 3 as well as Figure 4 Used to illustrate the inverse piezoelectric effect generated in piezoelectric elements.

[0081] According to one embodiment of the present invention, when a clamping operation is performed on the substrate W, the piezoelectric element 500 electrically connected to the electrode 212 is also powered by the power applied to the electrode 212, thus generating an inverse piezoelectric effect. That is, the piezoelectric element 500 inserted into the upper end of the pin hole 220 can expand (see figure). Figure 3 (a)). As the piezoelectric element 500 suitable for the pin hole 220 expands through the inverse piezoelectric effect, the diameter of the pin hole 220 can be reduced compared to the existing diameter (see (a)). Figure 4 (a) That is, if a power source is applied in order to generate an electrostatic force in the chuck component 210, a power source is also applied to the piezoelectric element 500 which is connected to the electrode 212 of the chuck component 210, and electrical energy is applied to the piezoelectric element 500, thereby causing mechanical deformation of the piezoelectric element 500 to expand, and the diameter of the pin hole 220 to decrease.

[0082] Conversely, if the substrate W is dechucking, the power supply previously applied to electrode 212 is cut off, and the power supply previously applied to piezoelectric element 500 is also cut off, thus eliminating the inverse piezoelectric effect. Therefore, the expanded piezoelectric element 500 can return to its original (normal) size (see reference). Figure 3 (b)). Subsequently, the reduced diameter of the pin hole 220 can be restored to its original diameter (see reference). Figure 4 (b) That is, if the power supply originally applied to the substrate chuck component 210 is cut off, the piezoelectric element 500 returns to its original state and the diameter of the pin hole 220 also returns to its original state.

[0083] Typically, the clamping of substrate W is performed while substrate W is being processed, and once the processing of substrate W is complete, the clamping of substrate W is released. Therefore, the diameter of the pin hole 220 can be reduced during the processing of substrate W.

[0084] If the piezoelectric element 500 expands and the diameter of the pin hole 220 decreases, the gap between the pin hole 220 and the lifting pin 240 disappears as the inner circumferential surface of the piezoelectric element 500 comes into close contact with the outer circumferential surface of the lifting pin 240. As a result, the likelihood of cooling gas frequently flowing in through the gap between the pin hole 220 and the lifting pin 240 decreases, and the possibility of particles generated inside the pin hole 220 due to the up-and-down movement of the lifting pin 240 flowing out through the gap between the pin hole 220 and the lifting pin 240 to the surface of the chuck component 210 is significantly reduced.

[0085] Furthermore, if the piezoelectric element 500 is made of a material with a higher volume resistivity than the dielectric disk 211, the resistance around the pin hole 220 increases, thereby reducing the possibility of plasma flowing in through the pin hole 220.

[0086] In this way, as the possibility of cooling gas and plasma flowing into the pin hole 220 decreases, the discharge phenomenon that once accompanied it inside the pin hole 220 can be prevented.

[0087] On the other hand, it is preferable that the piezoelectric element 500 is provided in a state of complete bonding within the pin hole 220 formed in the dielectric disk 21 by means of sintering or the like. Therefore, by using a material having a dielectric constant equal to that of the dielectric disk 211, the ease of bonding can be improved. For example, the piezoelectric element 500 can be a piezoelectric ceramic material having a dielectric constant equal to that of the dielectric disk 211 and having high volume resistivity.

[0088] On the other hand, although not shown in detail, the piezoelectric element 500 can be provided to receive power separately from the electrode 212. That is, the piezoelectric element 500 can be connected to a power source (not shown) that is independently controlled relative to the power source applied to the electrode 212 to receive electrical energy. The piezoelectric element 500 can receive electrical energy from a separate power source (not shown) and expand, thereby reducing the diameter of the pin hole 220, and can maintain (restore) its original state when no electrical energy is supplied.

[0089] As described above, a substrate processing method according to an embodiment of the present invention may include: a step of clamping the substrate; a step of performing plasma treatment on the clamped substrate; and a step of dechucking the substrate.

[0090] The step of clamping the substrate is performed by applying power to the electrode 212 built into the chuck component 210 to generate an electrostatic force on the substrate. At this time, electrical energy is also supplied to the piezoelectric element 500 electrically connected to the electrode 212, causing the piezoelectric element 500 to expand through the inverse piezoelectric effect, thereby reducing the inner circumferential diameter of the pin hole 220. The substrate clamping step is maintained during the plasma processing of the substrate. Therefore, during the plasma processing, the inner circumferential diameter of the pin hole 220 is maintained in a reduced state.

[0091] If the piezoelectric element 500 expands and the diameter of the pin hole 220 decreases, the gap that previously existed between the pin hole 220 and the lifting pin 240 disappears as the inner circumferential surface of the piezoelectric element 500 comes into close contact with the outer circumferential surface of the lifting pin 240. Consequently, the likelihood of cooling gas frequently flowing in through the gap between the pin hole 220 and the lifting pin 240 decreases, and the possibility of particles generated inside the pin hole 220 due to the up-and-down movement of the lifting pin 240 flowing out through the gap between the pin hole 220 and the lifting pin 240 to the surface of the chuck component 210 is significantly reduced.

[0092] Furthermore, if the piezoelectric element 500 is made of a material with a higher volume resistivity than the dielectric disk 211, the resistance around the pin hole 220 increases, thereby reducing the possibility of plasma flowing in through the pin hole 220.

[0093] Thus, as the possibility of cooling gas flowing into the pin hole 220 during the plasma processing through the expansion member 500 decreases, the discharge phenomenon that once accompanied it inside the pin hole 220 can be prevented.

[0094] If the plasma processing is completed, the substrate is released from clamping. During the release step, the power supply to the electrodes 212 of the chuck component 210 is cut off. Consequently, the power supply to the piezoelectric element 500 is also cut off, the inverse piezoelectric effect disappears, and the expanded piezoelectric element 500 can return to its original state. As the piezoelectric element 500 recovers, the reduced inner circumference length of the pin hole 220 can also be restored to its original length.

[0095] Subsequently, in order to remove the substrate that has completed the plasma processing from the processing space, the lifting pin 240 can be raised.

[0096] Figure 5 A flowchart illustrating a method for manufacturing an electrostatic chuck according to an embodiment of the present invention is shown.

[0097] An electrostatic chuck 200 according to an embodiment of the present invention includes an expansion member 500. The expansion member 500 is inserted into the upper end of a pin hole 220 formed in a chuck member 210, and includes an inner peripheral surface that, when expanded, abuts against the outer peripheral surface of a lifting pin 240 that is vertically accommodated in the pin hole 220. The normal inner peripheral size of the expansion member 500 is provided to be the same as the inner peripheral size of the pin hole 220. As an example, the expansion member 500 may be a piezoelectric element that expands by being powered by a power source.

[0098] The diameter of the pin hole 220 can be varied by means of an expansion member applied to the upper end of the pin hole 220 formed in a manner that passes through the chuck component 210.

[0099] A method for manufacturing an electrostatic chuck according to an embodiment of the present invention may include: step (S1) machining a pin hole 220 in a chuck component 210; step (S2) inserting an expansion member into the upper end of the pin hole 220; and step (S3) fixing the expansion member to the chuck component 210.

[0100] Step (S1) of machining the pin hole 220 is a step of machining the pin hole 220 in the chuck component 210 to accommodate a lift pin that can be raised and lowered. The pin hole 220 is machined in such a way that it penetrates both the top and bottom of the chuck component 210. This step may include a counter-boring step, which is machined in the shape of an expansion member 500 that is both the upper end of the pin hole 220 and the top of the chuck component 210. At least one pin hole 220 may be machined in the pin hole machining step (S1), and the pin hole 220 is machined before the electrostatic chuck is sintered.

[0101] A tubular piezoelectric element 500 can be inserted into the chuck component 210 after processing (S2). Specifically, the piezoelectric element 500 can be inserted into the dielectric disk 211. As a component exhibiting piezoelectricity, the piezoelectric element 500 can expand with the power supply. In addition, the piezoelectric element 500 can be a material with a higher volume resistivity than the dielectric disk 211, and can have the same dielectric constant as the dielectric disk 211.

[0102] The piezoelectric element 500 can be inserted to be electrically connected to the electrode 212. Alternatively, it can be connected to and inserted into another power source.

[0103] Then, the inserted piezoelectric element 500 can be fixed to the chuck component 210 (S3). The fixing step (S3) can be performed by sintering the electrostatic chuck with the piezoelectric element 500 inserted into the upper end of the pin hole 220. However, when machining the pin holes before sintering the electrostatic chuck, the spacing between the pin holes may become irregular due to shrinkage during sintering. Therefore, when machining the pin holes before sintering the electrostatic chuck, it is necessary to consider the shrinkage rate and accurately machine the pin holes to correspond to the set position. Alternatively, other bonding methods can be used to fix the piezoelectric element 500.

[0104] The normal internal diameter of the piezoelectric element 500 is formed to be the same as the diameter of the existing pin hole 220. That is, it is formed to be slightly larger than the diameter of the lifting pin 240. Specifically, it can be set to be the minimum diameter at which the lifting pin 240 does not contact the inner wall of the piezoelectric element 500 when the lifting pin 240 and the piezoelectric element 500 are configured to have the same central axis.

[0105] The piezoelectric element 500, electrically connected to electrode 212, can receive power during the clamping operation of the substrate W and generate an inverse piezoelectric effect. Specifically, the piezoelectric element 500 expands when power is applied. As the piezoelectric element 500 expands, its inner circumferential diameter decreases, thus reducing the inner circumferential diameter of the pin hole 220. The inner circumferential surface of the expanded piezoelectric element 500 can then be in close contact with the outer circumferential surface of the lifting pin 240.

[0106] When the substrate W is released from clamping, the expanded piezoelectric element 500 returns to its original shape, and the reduced diameter of the pin hole 220 also returns to its original shape. If the inverse piezoelectric effect occurs in the piezoelectric element 500 and the diameter of the pin hole 220 decreases, the gap between the pin hole 220 and the lifting pin 240 that once existed on the chuck component 210 can disappear. Therefore, plasma and cooling gas can be prevented from flowing into the pin hole 220, and particles can be prevented from flowing out of the pin hole 220 onto the surface of the chuck component 210. As a result, discharge (arc discharge) in the pin hole 220 and within the substrate processing apparatus can be minimized.

[0107] Above, refer to Figures 1 to 5An electrostatic chuck 200 according to an embodiment of the present invention, a substrate processing apparatus including the same, a substrate processing method, and a method for manufacturing the same are described. The electrostatic chuck 200 according to an embodiment of the present invention includes an expansion member 500 inserted into the inner periphery of a pin hole 220. The expansion member 500 can reversibly expand and recover, and when expanded, it can temporarily eliminate the fine gap existing between the pin hole 220 and the lift pin 240 by passing its inner peripheral surface in close contact with the outer peripheral surface of the lift pin 240. The expansion member 500 can be a piezoelectric element whose expansion is powered by a power source, and can remain in an expanded state during plasma processing. During plasma processing, if the expansion member 500 remains in an expanded state, plasma and cooling gas that have flowed into the pin hole 220 through the gap between the pin hole 220 and the lift pin 240 can be prevented from flowing in, and particles from inside the pin hole 220 can be prevented from flowing out onto the surface of the chuck member 210. Therefore, discharge (arc discharge) that may have occurred within the substrate processing apparatus as a result can be minimized.

[0108] On the other hand, the phenomenon of the piezoelectric element 500 is not limited to the examples described above, and can be applied to any form that reduces the upper part or the entire diameter of the pin hole 220. As an example, the piezoelectric element 500 can also be applied to the entire inner wall of the pin hole 220.

[0109] Furthermore, the above example illustrates a piezoelectric element 500 that expands when power is supplied to the expansion member applicable to the upper end of the pin hole 220. However, the form of the expansion member is not limited to this and can be any form that changes the diameter of the pin hole 220 as the expansion state and the recovery state are reversibly switched.

[0110] The above description is merely illustrative of the technical concept of the present invention. Those skilled in the art can make various modifications and variations without departing from the essential characteristics of the invention. Therefore, the embodiments disclosed in this invention are not intended to limit the technical concept of the invention, but rather to illustrate it. The scope of the technical concept of the invention is not limited to such embodiments. The scope of protection of this invention should be interpreted through the appended claims, and should be construed as including all technical concepts within the same scope as those claims within the scope of the invention.

Claims

1. An electrostatic chuck, comprising: The chuck component supports the base plate and is penetrated by at least one pin hole in the vertical direction, and the lifting pin can be vertically and flexibly accommodated in the pin hole; as well as An expansion member is provided on the inner periphery of the pin hole and is capable of expansion, and has an inner peripheral surface that, when expanded, is in close contact with the outer peripheral surface of the lifting pin received in the pin hole. The expansion component is a piezoelectric element that expands according to the power supply.

2. The electrostatic chuck according to claim 1, wherein, The electrostatic chuck further includes electrodes, which are built into the chuck component and generate electrostatic force.

3. The electrostatic chuck according to claim 2, wherein, The piezoelectric element is electrically connected to the electrode. If a power source is applied to the electrode, the piezoelectric element receives the power from the electrode and expands.

4. The electrostatic chuck according to claim 3, wherein, If the power supply to the electrode is cut off, the piezoelectric element returns to its state before expansion.

5. The electrostatic chuck according to claim 1, wherein, The chuck component is formed of a dielectric material. The piezoelectric element has the same dielectric constant as the chuck component, but with a higher volume resistivity compared to the chuck component.

6. The electrostatic chuck according to claim 5, wherein, The chuck component and the piezoelectric element are joined together by sintering.

7. The electrostatic chuck according to claim 2, wherein, The piezoelectric element and the electrode receive power separately and are controlled independently.

8. The electrostatic chuck according to claim 1, wherein, A receiving groove for accommodating the expansion component is formed at the upper end of the pin hole.

9. A substrate processing apparatus, comprising: The process chamber provides space for substrate processing; An electrostatic chuck is disposed in the substrate processing space; as well as A plasma generator is used to generate plasma in the substrate processing space. The electrostatic chuck includes: The chuck component supports the base plate and is penetrated by at least one pin hole in the vertical direction, and the lifting pin can be vertically and flexibly accommodated in the pin hole; as well as An expansion member is provided on the inner periphery of the pin hole and is capable of expansion, and has an inner peripheral surface that, when expanded, is in close contact with the outer peripheral surface of the lifting pin received in the pin hole. The expansion component is a tubular piezoelectric element that expands according to the supply of power.

10. The substrate processing apparatus according to claim 9, wherein, The piezoelectric element is electrically connected to the electrode that generates an electrostatic force in the electrostatic chuck. If a power source is applied to the electrode, the piezoelectric element receives the power from the electrode and expands toward the inside of the pin hole.

11. The substrate processing apparatus according to claim 10, wherein, If the power supply to the electrode is cut off, the piezoelectric element returns to its original state.

12. The substrate processing apparatus according to claim 9, wherein, The piezoelectric element is connected to a separately controlled power supply.

13. The substrate processing apparatus according to claim 9, wherein, The piezoelectric element has a higher volume resistivity than the chuck component.

14. A substrate processing method, comprising processing a substrate using an electrostatic chuck, wherein, The electrostatic chuck includes: The chuck component supports the base plate and is penetrated by at least one pin hole in the vertical direction, and the lifting pin can be vertically and flexibly accommodated in the pin hole; Electrodes, built into the chuck component, generate electrostatic force in the chuck component; and A piezoelectric element is provided on the inner periphery of the pin hole and is expandable, and has an inner peripheral surface that, when expanded, is in close contact with the outer peripheral surface of the lifting pin received in the pin hole. Plasma processing is performed in a state where the inner circumferential length of the pin hole decreases as the piezoelectric element expands when power is applied to the chuck component and the substrate is clamped.

15. The substrate processing method according to claim 14, wherein, If the plasma treatment is completed, when the power supply to the chuck component is cut off and the substrate is released from clamping, the piezoelectric element returns to its state before expansion, and the reduced inner circumference length of the pin hole returns to its length before reduction.

16. A method for manufacturing an electrostatic chuck, comprising: The steps for machining the pin hole for lifting the pin in a manner that passes through the top and bottom of the chuck component; The step of inserting an expansion member with an inner circumferential surface that, when expanded according to the power supply, fits tightly against the outer circumferential surface of the lifting pin at the upper end of the pin hole; and The step of fixing the inserted expansion component to the chuck component.

17. The method for manufacturing an electrostatic chuck according to claim 16, wherein, The expansion component is a tubular piezoelectric element with a higher volume resistivity compared to the chuck component.

18. The method for manufacturing an electrostatic chuck according to claim 16, wherein, The step of machining the pin hole includes countersinking the upper end of the pin hole in the shape of the expansion member.

19. The method for manufacturing an electrostatic chuck according to claim 16, wherein, At least one pin hole is formed in the chuck component.

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