Substrate processing apparatus and substrate processing method

Abstract

The present application relates to a substrate processing apparatus and a substrate processing method, and a substrate processing apparatus according to an embodiment of the present application includes: a chamber having a processing space inside; a substrate support unit disposed in the processing space and configured to support a substrate; an ion blocker disposed above the substrate support unit and dividing the processing space into an upper region where plasma is generated and a lower region; a gas supply unit configured to supply a fluorine-containing gas to the upper region; an upper electrode module disposed above the ion blocker and configured to supply the fluorine-containing gas to the upper region; and a high-frequency power supply module configured to apply power to the upper electrode module to generate the plasma in the upper region, and a coating layer for capturing fluorine radicals of the plasma is formed on at least a portion of a surface of the upper electrode module.

Description

Technical Field

[0001] This invention relates to a substrate processing apparatus and a substrate processing method. More specifically, it relates to a substrate processing apparatus and a substrate processing method for constantly maintaining an etching amount of polysilicon. Background Technology

[0002] In semiconductor devices such as Dynamic Random Access Memory (DRAM) and NAND Flash memory, there has been a recent trend toward drastically reducing critical dimension (CD) while simultaneously achieving high capacity.

[0003] In particular, as the integration of semiconductor devices increases and their functions become more diverse, polysilicon and silicon oxide films are widely used as patterning and insulating films for these devices. Polysilicon can be used as a material for gate electrodes, capacitor electrodes, conductive contacts, wiring, etc., while silicon oxide films are also used as insulating films and as hard masks for forming conductive patterns.

[0004] In semiconductor devices with both polysilicon and silicon oxide films, patterns need to be formed to utilize the polysilicon as wiring, electrodes, etc. When forming such patterns, it is important to selectively etch the silicon oxide film relative to the polysilicon. However, during this etching process, as the number of passes increases, the amount of polysilicon etched increases, leading to a problem where it becomes difficult to control the etch selectivity ratio between the polysilicon and the silicon oxide film. Summary of the Invention

[0005] The present invention addresses existing problems and relates to a substrate processing apparatus and method for maintaining a constant etching amount of polysilicon.

[0006] The problems to be solved by the present invention are not limited to those mentioned above, and those skilled in the art will clearly understand from the following description other problems not mentioned.

[0007] The substrate processing apparatus according to an embodiment of the present invention may include: a cavity having a processing space inside; a substrate support unit disposed in the processing space and used to support a substrate; an ion blocker disposed above the substrate support unit and dividing the processing space into an upper region and a lower region for generating plasma; a gas supply unit for supplying fluorine-containing gas to the upper region; an upper electrode module disposed above the ion blocker and supplying the fluorine-containing gas to the upper region; and a high-frequency power supply module for applying power to the upper electrode module to generate the plasma in the upper region, wherein a coating for capturing fluorine free radicals of the plasma is formed on at least a portion of the surface of the upper electrode module.

[0008] A substrate processing apparatus according to an embodiment of the present invention may include: a cavity having a processing space inside; a substrate support unit disposed in the processing space and used to support a substrate; an ion barrier disposed above the substrate support unit and dividing the processing space into an upper region and a lower region; a nozzle disposed below the ion barrier and dividing the lower region into a first region and a second region; a gas supply unit for supplying fluorine-containing gas to the upper region; an upper electrode module disposed above the ion barrier and supplying gas to the upper region; a high-frequency power supply module for applying power to the upper electrode module to generate plasma in the upper region; and a control unit for controlling the gas supply unit and the high-frequency power supply module, wherein the upper electrode module includes: a first electrode; a second electrode disposed below the first electrode; and a plate disposed below the second electrode, wherein a coating is formed on the surface of the upper electrode module, the coating comprising nickel.

[0009] According to an embodiment of the present invention, a substrate processing method is used to etch a substrate in a substrate processing apparatus, the substrate processing apparatus comprising: a cavity having a processing space therein; a substrate support unit disposed in the processing space and used to support the substrate; an ion barrier disposed above the substrate support unit and dividing the processing space into an upper region and a lower region; an upper electrode module disposed above the ion barrier and supplying a fluorine-containing gas to the upper region and including a nickel-containing coating in at least a portion thereof; and a high-frequency power supply module applying power to the upper electrode module to generate plasma in the upper region, the substrate processing method comprising: a plasma formation step of supplying a fluorine-containing gas to the upper region to form plasma; and an etching step of supplying a hydrogen-containing gas to the lower region, mixing free radicals in the plasma generated in the plasma formation step with the hydrogen-containing gas supplied to the lower region to form an etchant, and using the generated etchant to etch the substrate.

[0010] According to the present invention, by forming a nickel coating on the upper electrode module of the substrate processing apparatus, the amount of F free radicals reaching the substrate can be maintained constant.

[0011] In this way, even with an increase in the number of process iterations, the amount of F radicals reaching the substrate containing both polysilicon and silicon oxide remains constant, thus maintaining a constant etch amount of polysilicon. Consequently, the etch selectivity ratio between polysilicon and silicon oxide can be controlled.

[0012] Furthermore, by adjusting the ratio of fluorine-containing gas to hydrogen-containing gas supplied to the substrate, the etching selectivity between polycrystalline silicon and silicon oxide film can be controlled.

[0013] The effects of the present invention are not limited to those mentioned above. Those skilled in the art to which this invention pertains will clearly understand from the following description another effect not mentioned. Attached Figure Description

[0014] Figure 1 This is a diagram illustrating a substrate processing apparatus according to an embodiment of the present invention.

[0015] Figure 2 This is an enlarged view of the upper electrode module according to an embodiment of the present invention.

[0016] Figure 3 It is magnified and formed in Figure 1 A diagram of the coating of the substrate processing apparatus shown.

[0017] Figure 4 This is a diagram illustrating the flow of gas within a substrate processing apparatus according to an embodiment of the present invention.

[0018] Figure 5 This is a flowchart illustrating a substrate processing method according to an embodiment of the present invention.

[0019] Figure 6 This is a graph showing the amount of etching in polysilicon according to the number of processes according to an embodiment of the present invention.

[0020] Figure 7 This is a graph showing the etching amount of polycrystalline silicon according to the supply ratio of fluorine-containing gas and hydrogen-containing gas according to an embodiment of the present invention.

[0021] (Explanation of reference numerals in the attached diagram)

[0022] 10: Substrate processing apparatus

[0023] 100: Cavity

[0024] 200: Substrate support unit

[0025] 300: Upper electrode module

[0026] 400: Ion Blocker

[0027] 500: Sprayer head

[0028] 600: Gas Supply Unit

[0029] 700: Control Unit Detailed Implementation

[0030] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, so that those skilled in the art to which this invention pertains can readily implement it. However, the present invention can be implemented in various different ways and is not limited to the embodiments described herein.

[0031] When describing embodiments of the present invention, specific descriptions of known functions or structures are omitted when it is determined that such specific descriptions would unnecessarily obscure the spirit of the invention. Parts that perform similar functions and effects are referred to by the same reference numerals in all drawings.

[0032] At least some of the terminology used in this specification is defined with consideration of its function in this invention, and therefore may vary depending on the user's or operator's intent, conventions, etc. Consequently, the terminology should be interpreted based on the entire content of this specification.

[0033] Furthermore, in this specification, unless otherwise specified in the statements, the singular also includes the plural. In this specification, when a statement refers to the inclusion of a certain constituent element, unless specifically contradicted, it means that other constituent elements may be included, rather than excluding them.

[0034] On the other hand, in the accompanying drawings, for ease of understanding, the size or shape of the constituent elements, the thickness of the lines, etc., may be presented in a more or less enlarged manner.

[0035] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. When describing with reference to the accompanying drawings, the same or corresponding components are marked with the same reference numerals, regardless of the drawing numbers, and repeated descriptions of them are omitted.

[0036] According to an embodiment of the present invention, the substrate may be a substrate comprising polycrystalline silicon and a silicon oxide film on a silicon substrate.

[0037] Figure 1 This is a diagram illustrating a substrate processing apparatus according to an embodiment of the present invention.

[0038] Reference Figure 1 The substrate processing apparatus 10 may include a cavity 100, a substrate support unit 200, an upper electrode module 300, an ion blocker 400, a nozzle 500, a gas supply unit 600, and a control unit 700.

[0039] The cavity 100 has a processing space for performing plasma processes. Such a cavity 100 may have an exhaust port 102 at its lower part. The exhaust port 102 can be connected to an exhaust line equipped with a pump P. The exhaust port 102 can discharge reaction byproducts generated during the plasma process and residual gases inside the cavity 100 to the outside of the cavity 100 through the exhaust line. At this time, the internal space of the cavity 100 can be depressurized to a predetermined pressure.

[0040] The cavity 100 may have an opening 104 formed in its sidewall. The opening 104 can function as a passage for the substrate W to enter and exit the interior of the cavity 100. Such an opening 104 can be configured to be opened and closed by a door assembly.

[0041] The baffle unit 120 serves to exhaust plasma process byproducts and unreacted gases. The baffle unit 120 can be disposed between the inner wall of the cavity 100 and the electrostatic chuck 220. The baffle unit 120 can be provided in an annular shape and can have multiple through holes extending vertically. The flow of process gas can be controlled according to the number and shape of the through holes in the baffle unit 120.

[0042] The substrate support unit 200 can be disposed in the processing space of the cavity 100. Such a substrate support unit 200 can support the substrate W by electrostatic force. However, this embodiment is not limited to this, and the substrate W can be supported by various methods such as mechanical clamping or vacuum.

[0043] When the substrate support unit 200 supports the substrate W using electrostatic force, it may include an electrostatic chuck 220 comprising a base member 222 and a clamping member 224. The base member 222 supports the clamping member 224. The base member 222 may be provided as an aluminum substrate, for example, made of aluminum. The clamping member 224 supports the substrate W placed thereon using electrostatic force. Such a clamping member 224 may be made of ceramic material and provided as a ceramic plate or ceramic locator, and may be combined with the base member 222 to be fixed to the base member 222. Although not shown, a bonding layer may be formed between the base member 222 and the clamping member 224 formed thereon.

[0044] A heating element 226 and a cooling element 228 may be provided within the substrate component 222 or the clamping component 224 to maintain the substrate W at the process temperature during the process. The heating element 226 may be provided as a hot wire, and the cooling element 228 may be provided as a cooling wire for refrigerant flow. According to an embodiment of the invention, the temperature of the substrate W can be adjusted by setting the heating element 226 to a high temperature (e.g., 40°C) during the execution of the process.

[0045] The ring assembly 240 can be disposed at the edge region of the substrate support unit 200. The ring assembly 240 can have a ring shape and be disposed around the electrostatic chuck 220. The ring assembly 240 can have a focusing ring 242 and an insulating ring 244. The focusing ring 242 can be provided to surround the electrostatic chuck 220, concentrating plasma towards the substrate W. The insulating ring 244 can be provided to surround the focusing ring 242. Optionally, the ring assembly 240 may include an edge ring (not shown) provided close to the periphery of the focusing ring 242 to prevent damage to the sides of the electrostatic chuck 220 by plasma. The focusing ring 242 can be made of silicon, and the insulating ring 244 can be made of quartz. Unlike the above, the structure of the ring assembly 240 can be varied.

[0046] The substrate support unit 200 may include a drive unit 260. The drive unit 260 can raise and lower the substrate support unit 200 according to the process. The drive unit 260 may use a hydraulic cylinder, a pneumatic cylinder, etc., but is not limited to these.

[0047] Unlike the illustration, the substrate support unit 200 can be a metal stage instead of an electrostatic chuck. The metal stage can support the substrate W and may not include vacuum holes or clamping electrodes for fixing the substrate W. The metal stage can be raised and lowered to adjust its distance from the nozzle 500 described later. The surface of the metal stage (the entire surface exposed to the etchant) can be coated by the lower region coating 570 described later. A heating element can be embedded in the metal stage; additionally, the heating element can be set to a high temperature (e.g., 40°C) to regulate the temperature of the substrate W.

[0048] An upper electrode module 300, an ion blocker 400, and a nozzle 500 can be configured above the substrate support unit 200.

[0049] Figure 2 This is a diagram illustrating an upper electrode module according to an embodiment of the present invention.

[0050] Reference Figure 2 The upper electrode module 300 can change the ratio of the gas supplied from the gas supply unit 600 (described later) according to the supply area, and includes a first electrode 320, a second electrode 340, and a plate 360.

[0051] The first electrode 320 may be disposed in a disk shape at the uppermost part of the cavity 100. The first electrode 320 may be made of a metallic material and may form a gas inlet 322 for transmitting gas supplied from the gas supply unit 600 (described later) into the cavity 100. According to one embodiment of the present invention, only one gas inlet 322 formed on the first electrode 320 is shown, but it is not limited thereto, and multiple gas inlets may also be formed.

[0052] The second electrode 340 can be disposed below the first electrode 320 and has a disk shape. The second electrode 340 can be made of a metallic material and can include multiple second electrode holes 342 for transmitting gas supplied through the first electrode 320 into the cavity 100. The second electrode holes 342 can be arranged radially across the entire second electrode 340. Gas supplied from the gas inlet 322 can be uniformly distributed in the space between the second electrode 340 and the first electrode 320.

[0053] Plate 360 ​​can be positioned below the second electrode 340, allowing gas supplied from the gas supply unit 600 (described later) to flow upwards to region S. 10 Provided for transmission. Plate 360 ​​can be made of metal and shaped like a disk. Plate 360 ​​can be used to direct the received gas upwards to region S. 10 Multiple supply holes 362 are formed to supply gas, and these holes 362 can be arranged radially across the entire plate 360. Gas supplied from the multiple second electrode holes 342 can be uniformly distributed in the space between the plate 360 ​​and the second electrode 340. Unlike the illustration, the second electrode 340 can be omitted; in this case, gas supplied from the gas inlet 322 can also be uniformly distributed in the space between the first electrode 320 and the plate 360. The number of electrodes or plates can be appropriately selected to achieve uniform gas distribution in the aforementioned space.

[0054] Refer again Figure 1 A first insulating ring 140 can be formed below the upper electrode module 300. The first insulating ring 140 can be ring-shaped and can be formed of an insulator.

[0055] The ion blocker 400 can be configured below the first insulating ring 140 and above the nozzle 500, facing the bottom surface of the cavity 100. The ion blocker 400 can divide the processing space inside the cavity 100 into an upper region S. 10 and lower region S 20 The ion blocker 400 can be made of silicon or metal. The ion blocker 400 can be disk-shaped; for example, it can be disc-shaped. Multiple through holes 400a can be formed in the ion blocker 400. The top of the ion blocker 400 can face the bottom of the plate 360.

[0056] A second insulating ring 160 can be formed below the ion blocker 400. The second insulating ring 160 can be ring-shaped and can be formed of an insulator. The interior of the second insulating ring 160 can provide space for heating the lower region S. 20 The first region S in 22The ring heating element 162, as an example, can be a heating coil. According to an embodiment of the present invention, by heating the second insulating ring 160 using the ring heating element 162, residues remaining in the first region S can be removed. 22 The particles inside.

[0057] The nozzle 500 can be positioned below the ion blocker 400, facing the substrate support unit 200. The nozzle 500 can direct the lower region S 20 Divided into the first region S 22 Second region S 24 The nozzle 500 can be made of silicon or metal. The nozzle 500 can be disc-shaped, for example, it can be circular. Multiple gas injection holes 500a can be formed in the nozzle 500 to supply gas.

[0058] A high-frequency power supply module 380 can be connected to the upper electrode module 300. The high-frequency power supply module 380 can apply RF power to the upper electrode module 300 to excite the gas supplied to the cavity 100, thereby generating plasma inside the cavity 100. According to one embodiment of the present invention, plasma can be generated using a capacitively coupled plasma source (CCP), but the present invention is not limited thereto. As an example, plasma can be generated using an inductively coupled plasma source (ICP).

[0059] The high-frequency power supply module 380 may include a high-frequency power supply 382 and an impedance matching circuit 384. The ion blocker 400 and the nozzle 500 may be grounded.

[0060] According to an embodiment of the present invention, the space divided by the plate 360, the first insulating ring 140, and the ion blocker 400 in the upper electrode module 300 is the upper region S. 10 Upper region S 10 This can be a region that receives gas supplied from the first gas supply unit 620 of the gas supply unit 600 (described later) to form plasma. Upper region S 10 This can be called a plasma region. It can be, in the upper region S... 10 Plasma effluents such as free radicals, ions, or electrons are formed. Ion blockers 400 filter the ions, and the remaining plasma effluents pass through ion blockers 400 into the downward region S. 20 transmission.

[0061] In addition, the space divided by the ion blocker 400, the second insulating ring 160, and the nozzle 500 is the lower region S. 20 The first region S in22 It can be in the upper region S 10 The region through which free radicals in the plasma formed in the first region S pass. 22 This can be called the ion filtering region. Lower region S 20 The second region S in 24 It can receive gas supplied from the second gas supply unit 640 of the gas supply unit 600 described later, and in the upper region S 10 The region where free radicals in the plasma formed in the plasma mix to generate the etchant. Additionally, the second region S... 24 It can be a substrate processing space that uses the generated etchant to perform substrate processing processes.

[0062] Figure 3 This is an enlarged view of the coating formed on a substrate processing apparatus according to an embodiment of the present invention.

[0063] According to one embodiment of the present invention, an upper electrode module coating 370 may be formed on the upper electrode module 300. The upper electrode module coating 370 may be formed on the first electrode 320, the second electrode 340, and the plate 360. More specifically, the upper electrode module coating 370 may be formed on at least a portion or entirely of the underside of the first electrode 320 exposed to gas supplied from the first gas supply unit 620, the inner side of the gas inlet 322, the upper / lower / inner side of the second electrode 340, the inner side of the plurality of second electrode holes 342, and the upper / inner side of the plate 360 ​​and the inner side of the plurality of supply holes 362. The upper electrode module coating 370 may contain nickel (Ni). The upper electrode module coating 370 may also contain phosphorus (P). According to one embodiment of the present invention, by forming a nickel coating 370 on the upper electrode module 300, scavenging, i.e., capturing, the amount of F free radicals, can be achieved. This allows F radicals to be captured in the nickel coating 370, thus maintaining a constant amount of F radicals supplied inside the cavity 100, thereby ensuring a constant amount of polysilicon etching even with increased process cycles.

[0064] In the upper region S 10 An upper region coating 470 can be formed. The upper region coating 470 can be formed on the underside of the plate 360, the inner side of the first insulating ring 140, and the top of the ion barrier 400. More specifically, it can be formed on the surface exposed to the upper region S. 10 At least a portion or all of the surfaces of the plasma-generated plate 360, the first insulating ring 140, and the ion barrier 400 are formed with an upper region coating 470. The upper region coating 470 may be a ceramic coating (e.g., yttrium oxide (Y2O3)) with excellent plasma resistance. In another example, the upper region coating 470 may also be an anodized aluminum coating.

[0065] In the lower region S 20 A lower region coating 570 can be formed. Specifically, the lower region coating 570 can be formed on at least a portion or entirely of the following: below the ion blocker 400; the inner side of the second insulating ring 160; the upper / lower surface of the nozzle 500; the inner side of the plurality of gas injection holes 500a; the inner wall of the cavity 100; the upper and lower surfaces of the baffle unit 120; the inner side of the holes of the baffle unit 120; the inner wall of the cavity 100 from the baffle unit 120 to the exhaust port 102; the sides and bottom of the substrate support unit 200; and the upper surface and sides of the substrate support unit 200. The lower region coating 570 may contain nickel (Ni). The lower region coating 570 may also contain phosphorus (P). By forming the lower region coating 570, unreacted F radicals can be captured or particles inside the cavity 100 generated by process gases can be minimized.

[0066] Refer again Figure 1 The gas supply unit 600 can supply gases required for substrate W processing, etc., to the cavity 100. According to an embodiment of the present invention, the gas supply unit 600 may include a first gas supply unit 620 and a second gas supply unit 640.

[0067] Each gas supply unit 620, 640 may include gas supply sources 622, 642, gas supply lines 624, 644, and gas injection nozzles. Gas supply lines 624, 644 may connect gas supply sources 622, 642 and gas injection nozzles. Gas valves 626, 646 may be provided on gas supply lines 624, 644 for opening and closing their passages or regulating the flow rate of fluid flowing through their passages.

[0068] The first gas supply unit 620 may include a gas supply source 622 and a gas supply line 624 for supplying gas to the internal space of the cavity 100. A gas valve 626 for regulating the flow rate of the supplied gas may be provided on the gas supply line 624. Specifically, the first gas supply unit 620 may extend upwards to region S. 10 Gas supply. According to an embodiment of the present invention, the gas supplied from the first gas supply unit 620 is a fluorine-containing gas, which is any one of NF3, SF6, SiF4 and XeF2.

[0069] Additionally, the first gas supply unit 620 may also include a gas supply source 632, a gas supply line 634, and a gas valve 636 for supplying an inert gas along with the fluorine-containing gas. The inert gas may be any one of Ar, He, Xe, and N2.

[0070] The second gas supply unit 640 may include a gas supply source 642 and a gas supply line 644 for supplying gas to the internal space of the cavity 100. A gas valve 646 for regulating the flow rate of the supplied gas may be provided on the gas supply line 644. Specifically, the second gas supply unit 640 may be connected to the nozzle 500 and extend downwards to the region S. 20 The second region S in 24 Gas supply. According to an embodiment of the present invention, the gas supplied from the second gas supply unit 640 may be a hydrogen-containing gas, which is any one of NH3, CH4 and C4H8.

[0071] Additionally, the second gas supply unit 640 may also include a gas supply source 652, a gas supply line 654, and a gas valve 656 for supplying an inert gas along with hydrogen-containing gas. The inert gas may be any one of Ar, He, Xe, and N2.

[0072] Figure 4 This is a diagram illustrating the gas flow in the upper and lower regions according to an embodiment of the present invention.

[0073] Reference Figure 4 It can be that the first gas supply unit 620 passes through the upper electrode module 300 to the upward region S. 10 A fluorine-containing gas is supplied, and the supplied gas is converted into a plasma state by the high-frequency power module 380 of the upper electrode module 300. Specifically, the fluorine-containing gas can decompose into ions, electrons, and F radicals as it is converted into a plasma state. Alternatively, the ions and electrons can be absorbed by the ion blocker 400, and the F radicals can be released into the downward region S. 20 The first region S in 22 Movement. The F radical can move through the first region S. 22 To the second region S 24 Supply. Gas is supplied from the second gas supply unit 640 connected to the nozzle 500 to the second area S. 24 The supplied hydrogen-containing gas can react with free radicals in the plasma generated from the first gas supply unit 620, passing through the ion barrier 400 and the nozzle 500, to generate an etchant. This etchant is then directed to the second region S. 24 The supplied hydrogen-containing gas and in the upper region S 10 Generated in the middle and through the lower region S 20 The first region S in 22 To the second region S 24The supplied F radicals can react to generate HF or NH4F (F* + NH3 → NH4F or HF). HF or NH4F can react with SiO2 on the surface of the substrate W to generate (NH4)2SiF6 or H2O (NH4F4 + 4HF + SiO2 → (NH4)2SiF6 + 2H2O). (NH4)2SiF6 can also be removed by heating through the substrate support unit 200 and through the exhaust port 102 ((NH4)2SiF6 → SiF4 + 2NH3 + 2HF). Based on the above operation, the substrate processing apparatus 10 can etch the silicon oxide film (SiO2) on the substrate W.

[0074] Refer again Figure 1 The control unit 700 can comprehensively control the operation of the substrate processing apparatus 10 configured as described above. The control unit 700 can be, for example, a computer, and includes auxiliary storage devices. The CPU (Central Processing Unit) can operate based on programs or processing conditions stored in ROM (Read-Only Memory) or auxiliary storage devices, controlling the overall operation of the substrate processing apparatus 10. Furthermore, programs that can be read by the computer can be stored on a storage medium. Examples of storage media include flexible optical discs, CDs (Compact Discs), CD-ROMs (Read-Only Optical Discs), hard disks, flash memory, or DVDs (Digital Video Optical Discs). The control unit 700 can be located inside or outside the substrate processing apparatus 10. When the control unit 700 is located externally, it can control the substrate processing apparatus 10 via wired or wireless communication methods.

[0075] According to an embodiment of the present invention, the control unit 700 can control the heating member 226 to set the temperature of the substrate support unit 200 to 40°C or higher during the process of processing the substrate W, and control the ring heating member 162 to set the inner wall temperature of the cavity 100 to 60°C or higher. Furthermore, the control unit 700 can control the supply to the upper region S 10 and the lower region S 20 The second region S in 24 The supply of fluorine-containing gases and hydrogen-containing gases.

[0076] Figure 5 This is a flowchart of a substrate processing method according to an embodiment of the present invention. The substrate processing method of the present invention utilizes... Figure 1 The substrate processing apparatus will therefore refer to all of them. Figure 1 as well as Figure 5 Please provide an explanation.

[0077] Reference Figure 1 as well as Figure 5The method for etching a substrate may include: a plasma formation step (S100), in which plasma is drawn from a first gas supply unit upwards into region S. 10 Plasma is formed by supplying fluorine-containing gas; etching step (S200), downward region S 20 The second region S in 24 Hydrogen-containing gas is supplied to the second region S, along with free radicals from the plasma generated during the plasma formation step. 20 The hydrogen-containing gas is mixed to form an etchant, and the substrate is etched using the generated etchant. The plasma formation step to the etching step (S100-S200) can be performed as a cycle, repeated at least once to etch the substrate W to the desired thickness. Such a substrate processing method can be performed at a temperature of 40°C or higher.

[0078] The plasma formation step (S100) is from the first gas supply unit 620 upward to region S 10 The step of supplying gas to form plasma. This could be, from the first gas supply unit 620 upwards to region S... 10 A fluorine-containing gas is supplied and plasma-injected. The fluorine-containing gas supplied from the first gas supply unit 620 to the upward region S10 can be any one of NF3, SF6, SiF4, and XeF2. According to an embodiment of the present invention, the fluorine-containing gas supplied from the first gas supply unit 620 to the upward region S10... 10 The supplied gas can be NF3, but is not limited to it. Upward region S 10 The supplied NF3 gas can be converted into a plasma state. During this conversion, it can decompose into ions, electrons, and free radicals. As an example, the NF3 of this invention can be plasma-entrained and decomposed into F free radicals and NF2 ions. Alternatively, the generated free radical components can be deflected downwards into region S through the ion barrier 400. 20 The moving ions and electrons are absorbed by the ion blocker 400.

[0079] The etching step (S200) is the step of generating an etchant and using the generated etchant to etch the substrate W. This can be done by moving the etchant downwards from the second gas supply unit 640 to the region S. 20 The second region S in 24 Hydrogen-containing gas is supplied, and the supplied hydrogen-containing gas passes through the ion barrier 400 and the lower region S in the plasma formation step (S100). 20 The first region S in 22 And the supply to the second region S 24 The free radicals mix to generate an etchant. The generated etchant can be used simultaneously to etch the substrate W. Gas is supplied from the second gas supply unit 640 to the second region S. 24The supplied hydrogen-containing gas can be any one of NH3, CH4, and C4H8. According to an embodiment of the present invention, from the second gas supply unit 640 to the second region S 24 The supplied gas can be NH3. The etchants generated using it are NH4F and HF, and the unreacted F radicals are directly supplied to the substrate W. The silicon oxide film can etch the surface layer of the silicon oxide film while reacting with the generated etchant to produce volatile etch by-products. In the case of polysilicon, etching can be performed by the unreacted F radicals.

[0080] The etching amount of polysilicon was confirmed using the substrate processing apparatus and the substrate processing method of the present invention.

[0081] Figure 6 is a graph showing the etching amount of polysilicon according to the number of processes. In the case of a, b, c, d, e shown on the X-axis of Figure 6 , there is a relationship of a < b < c < d < e, which means that a is the smallest and e is the largest. In addition, in the case of A, B, C, D, E shown on the Y-axis, there is a relationship of A < B < C < D < E, which means that A is the smallest and E is the largest. In the case of A', it exists between A and B, meaning that there is a relationship of A < A' < B.

[0082] In Figure 6 , the embodiment shows a graph of the etching amount of polysilicon according to the number of substrate processing times when the substrate W is processed by the substrate processing apparatus 10 described above in Figures 1 to 4 . The path from the first gas supply unit 620 to the substrate W can correspond to the upper electrode module 300 having the upper electrode module coating 370 containing nickel (Ni), the upper region S having the upper region coating 470 including a ceramic coating 10 and the lower region S having the lower region coating 570 containing nickel (Ni) 20 .

[0083] In Figure 6 , the comparative example shows a case where the upper electrode module 300 is anodized coated instead of nickel (Ni) coated, different from the embodiment. In the comparative example, the path from the first gas supply unit 620 to the substrate W can correspond to the anodized coated upper electrode module, the upper region S having the upper region coating 470 including a ceramic coating 10 and the lower region S having the lower region coating 570 containing nickel (Ni) 20 . The difference between the comparative example and the embodiment lies in whether the region before reaching the upper region S where plasma is generated from the gas inlet 322 10 is coated with nickel (Ni) or anodized.

[0084] Refer to Figure 6, it can be known that when etching a polysilicon substrate using an existing anodic oxidation-coated upper electrode module, as the number of processes increases, the etching amount of the polysilicon also increases. Specifically, when using an anodic oxidation-coated upper electrode module, as the number of processes increases, the reaction between Al2O3 and F radicals decreases while the amount of F radicals increases compared to the initial amount, thus causing the etching amount of the polysilicon to also increase.

[0085] It can be known that when etching a polysilicon substrate using the nickel-coated upper electrode module 300 of the present invention, even if the number of processes increases, the etching amount of the polysilicon is constant. Specifically, the amount of F radicals is constantly captured by the nickel-coated upper electrode module, so even if the number of processes increases, the etching amount of the polysilicon is constantly maintained. In particular, according to the process conditions, in the upper region S 10 the F radicals can flow countercurrently to the upper electrode module 300 instead of the lower region S 20 . Therefore, different from the comparative example in which nickel (Ni) coating treatment is only performed on the lower region S 10 with reference to the upper region S 20 which is the region where plasma is generated, in the embodiment in which nickel (Ni) coating treatment is performed up to the upper electrode module 300 located above with reference to the upper region S 10 which is the region where plasma is generated, the etching amount of the polysilicon can be maintained more constantly.

[0086] Figure 7 is a graph showing the etching amount of polysilicon according to the supply ratio of a fluorine-containing gas and a hydrogen-containing gas in a substrate processing apparatus including a nickel-coated upper electrode module according to an embodiment of the present invention.

[0087] Referring to Figure 7 , it is a graph showing that the total amount of gas supplied into the cavity by the gas supply unit is constantly maintained and the etching amount of polysilicon according to the change in the supply ratio of NF3 gas. In Figure 7 the cases of a, b, c, d, e, f, g, h shown on the X-axis of, there is a relationship of a < b < c < d < e < f < g < h. This means that the supply ratio of NF3 gas for a is the smallest and the supply ratio of NF3 gas for h is the largest. Additionally, in the cases of A, B, C, D, E, F, G, H shown on the Y-axis, there is a relationship of A < B < C < D < E < F < G < H, which means that A is the smallest and H is the largest.

[0088] As the results above show, the etch amount of polysilicon increases with the increase in the NF3 gas supply ratio. This means that with a nickel-coated top electrode module, the etch amount of polysilicon can be accurately controlled even with increased process cycles. If no nickel coating is formed on the top electrode module, the etch amount of polysilicon continues to change during process execution, making it difficult to control. Therefore, by forming a nickel coating on the top electrode module, the selectivity ratio between polysilicon and silicon oxide can be controlled even with increased process cycles, thus improving process yield.

[0089] The above description is merely an illustrative account 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 described herein are for illustrating the technical concept of the invention and are not intended to limit it. The technical concept of the invention is not limited to such embodiments. The scope of protection of the present invention should be interpreted through the appended claims, and all technical concepts within the same scope should be included within the scope of the claims.

Claims

1. A substrate processing apparatus, comprising: The cavity has processing space inside; A substrate support unit is disposed in the processing space and is used to support the substrate; An ion blocker is disposed above the substrate support unit and divides the processing space into an upper region and a lower region for generating plasma. A gas supply unit is used to supply fluorine-containing gas to the upper region; An upper electrode module is positioned above the ion blocker and supplies the fluorine-containing gas to the upper region. as well as A high-frequency power supply module applies power to the upper electrode module to generate the plasma in the upper region. A coating for capturing fluorine radicals of the plasma is formed on at least a portion of the surface of the upper electrode module.

2. The substrate processing apparatus according to claim 1, wherein, The coating contains nickel.

3. The substrate processing apparatus according to claim 2, wherein, The upper electrode module includes: First electrode; The second electrode is disposed below the first electrode; and A plate is positioned below the second electrode.

4. The substrate processing apparatus according to claim 1, wherein, An upper region coating is formed in the upper region. The upper region coating contains Y2O3.

5. The substrate processing apparatus according to claim 1, wherein, A lower region coating is formed in the lower region. The lower region coating contains nickel.

6. The substrate processing apparatus according to claim 1, wherein, The gas supply unit includes: A first gas supply unit is used to supply fluorine-containing gas to the upper region; and The second gas supply unit is used to supply hydrogen-containing gas to the lower region.

7. The substrate processing apparatus according to claim 6, wherein, The fluorine-containing gas is any one of NF3, SF6, SiF4, and XeF2.

8. The substrate processing apparatus according to claim 6, wherein, The hydrogen-containing gas is any one of NH3, CH4, and C4H8.

9. The substrate processing apparatus according to claim 6, wherein, The substrate processing apparatus further includes: The nozzle is positioned below the ion blocker, dividing the lower region into a first region and a second region. The first region in the lower region is the region from which the fluorine radicals are transported from the plasma through the ion barrier, and the second region in the lower region is the region where the fluorine radicals passing through the first region are mixed with the hydrogen-containing gas to form an etchant and where a substrate processing process is performed.

10. A substrate processing apparatus, comprising: The cavity has processing space inside; A substrate support unit is disposed in the processing space and is used to support the substrate; An ion blocker is disposed above the substrate support unit and divides the processing space into an upper region and a lower region; The nozzle is positioned below the ion blocker and divides the lower region into a first region and a second region. A gas supply unit is used to supply fluorine-containing gas to the upper region; An upper electrode module is disposed above the ion blocker and supplies gas to the upper region; A high-frequency power supply module applies power to the upper electrode module to generate plasma in the upper region; as well as The control unit is used to control the gas supply unit and the high-frequency power supply module. The upper electrode module includes: First electrode; The second electrode is disposed below the first electrode; and A plate is positioned below the second electrode. A coating comprising nickel is formed on the surface of the upper electrode module.

11. The substrate processing apparatus according to claim 10, wherein, An upper region coating is formed in the upper region. The upper region coating contains Y2O3.

12. The substrate processing apparatus according to claim 10, wherein, A lower region coating is formed in the lower region. The lower region coating contains nickel.

13. The substrate processing apparatus according to claim 10, wherein, The gas supply unit includes: A first gas supply unit is used to supply fluorine-containing gas to the upper region; and The second gas supply unit is used to supply hydrogen-containing gas to the second region of the lower region.

14. The substrate processing apparatus according to claim 13, wherein, The fluorine-containing gas is any one of NF3, SF6, SiF4, and XeF2. The hydrogen-containing gas is any one of NH3, CH4, and C4H8.

15. A substrate processing method for etching a substrate in a substrate processing apparatus, the substrate processing apparatus comprising: The cavity has processing space inside; A substrate support unit is disposed in the processing space and is used to support the substrate; An ion blocker is disposed above the substrate support unit and divides the processing space into an upper region and a lower region; An upper electrode module is disposed above the ion blocker and supplies fluorine-containing gas to the upper region and includes a nickel-containing coating in at least a portion thereof; and a high-frequency power supply module, which applies power to the upper electrode module to generate plasma in the upper region, wherein, The substrate processing method includes: The plasma formation step involves supplying a fluorine-containing gas to the upper region to form plasma; and In the etching step, hydrogen-containing gas is supplied to the lower region, and free radicals in the plasma generated in the plasma formation step are mixed with the hydrogen-containing gas supplied to the lower region to form an etchant, and the substrate is etched using the generated etchant.

16. The substrate processing method according to claim 15, wherein, The cycle, including the plasma formation step and the etching step, is repeated at least once.

17. The substrate processing method according to claim 15, wherein, The substrate comprises polycrystalline silicon and a silicon oxide film.

18. The substrate processing method according to claim 15, wherein, The free radicals that are mixed with the hydrogen-containing gas in the etching step to form the etchant are fluorine free radicals.

19. The substrate processing method according to claim 15, wherein, The etchant formed in the etching step is HF or NH4F.

20. The substrate processing method according to claim 15, wherein, The upper electrode module includes: First electrode; The second electrode is disposed below the first electrode; and A plate, disposed below the second electrode, has multiple holes formed therein. The coating is formed on the inner sides of the plurality of holes and on the top surface of the plate.

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