Substrate processing apparatus and plasma density control method

Abstract

The invention relates to a substrate processing apparatus and a plasma density control method, and more specifically provides a technology capable of controlling plasma density distribution by applying a geometric structure of a shielding baffle plate as a plasma adjusting medium parameter in the substrate processing apparatus. An embodiment of a substrate processing apparatus includes: a cavity providing a process space; a substrate support unit provided in the process space, on which a substrate is placed and which supports the substrate, the substrate support unit including an edge ring attached to an outer contour of the substrate; a shutter unit disposed on the periphery of the substrate supporting unit and including an upper shutter provided with a vent hole and capable of rising and falling, a lower shutter positioned below the upper shutter, and an upper shutter raising and falling portion for raising and falling the upper shutter; and a control unit for adjusting the plasma density distribution by applying the exhaust hole of the upper baffle plate and the height caused by the lifting of the upper baffle plate as a plasma adjustment medium parameter.

Description

Technical Field

[0001] This invention relates to a substrate processing apparatus and a plasma density control method, and more specifically to a technique that allows the application of the geometry of a shielding baffle in the substrate processing apparatus as a plasma adjustment medium parameter to control the plasma density distribution. Background Technology

[0002] Various processes that utilize plasma to treat substrates are commonly used in the manufacturing of semiconductor devices. Such processes include etching and vapor deposition, which are employed in various semiconductor manufacturing processes.

[0003] Plasma-based substrate processing devices can inject process gases into the internal space of a cavity, exciting them into a plasma state to perform plasma processes.

[0004] In a substrate processing apparatus, a baffle unit can be provided to regulate the pressure while discharging gas from the interior space of the exhaust chamber, and at the same time perform a shielding function for plasma distribution.

[0005] More precise adjustments are needed to the geometry of the shielding baffles in such baffle units to control plasma distribution.

[0006] Furthermore, in the application of substrate processing technology, when gas is discharged through the baffle unit, foreign matter such as polymers diffuses from areas that are not in the process area to the process area, thus contaminating the entire equipment and causing a decrease in process yield.

[0007] (Patent Document 1) Patent Document 01: Korean Patent Publication No. 10-2022-0075966

[0008] (Patent Document 1) Patent Document 02: Korean Patent Publication No. 10-955575 Summary of the Invention

[0009] This invention is proposed to solve the problems of the prior art as described above, and aims to provide a solution for controlling plasma density distribution by applying the geometry of a shielding baffle to the parameters of a plasma adjustment medium.

[0010] Furthermore, it is necessary to address the issue of contamination of the entire equipment and a decrease in process yield caused by foreign matter such as polymers spreading from areas outside the process area to the process area when gas is discharged through the baffle unit.

[0011] The purpose of this invention is not limited to the foregoing objectives, and other objectives and advantages of the invention not mentioned can be understood from the following description.

[0012] An embodiment of the substrate processing apparatus according to the present invention for solving the above-mentioned problems may include: a cavity providing a process space; a substrate support unit disposed in the process space and on which a substrate is placed and supported, and including an edge ring mounted on the outer contour of the substrate; a baffle unit disposed around the substrate support unit and including an upper baffle, a lower baffle, and an upper baffle lifting portion, the upper baffle having an exhaust port and being movable, the lower baffle being located below the upper baffle, and the upper baffle lifting portion causing the upper baffle to move up and down; and a control unit that uses the exhaust port of the upper baffle and the height resulting from the movement of the upper baffle as plasma adjustment medium parameters to adjust the plasma density distribution.

[0013] As an example, the upper baffle may be an annular plate with the exhaust hole, while the lower baffle may be an annular plate without the exhaust hole.

[0014] As an example, the control unit may adjust the height of the upper baffle by lowering the upper baffle based on the height of the edge ring.

[0015] As an example, the baffle unit may further include an exhaust port adjustment component for adjusting the size of the exhaust port of the upper baffle.

[0016] As an example, the control unit may adjust one or more of the size of the exhaust port and the height of the upper baffle according to the required plasma density distribution.

[0017] As an example, the control unit may adjust the height of the upper baffle according to the required plasma density distribution while the size of the exhaust port is fixed.

[0018] As an example, the diameter of the exhaust port of the upper baffle can be selected within a range of less than 10 mm.

[0019] As an example, the height of the upper baffle may be a descending height selected within a range of 40 mm or less, based on the edge ring of the substrate support unit.

[0020] As an example, the baffle unit may further include an exhaust component that discharges gas through the upper baffle and the lower baffle.

[0021] As an example, the baffle unit may be such that the upper baffle contacts the lower baffle, thereby blocking the process space from the space below the lower baffle.

[0022] As an example, the cavity may have a passageway formed on one side wall. The cavity may also include: a door that selectively opens or closes the passageway corresponding to the passageway; and a gasket that contacts or is adjacent to the inner side wall of the cavity. The gasket includes: an upper gasket disposed above the passageway on the inner side wall of the cavity; and a lower gasket whose lower end is connected to the outside of the upper baffle and has a heating element to regulate the temperature of the upper baffle through heat conduction, and selectively opens or closes the passageway according to the raising or lowering of the upper baffle.

[0023] Alternatively, one embodiment of the plasma density control method according to the present invention may include: a contour confirmation step, confirming the geometric contour of a baffle unit corresponding to a desired plasma density distribution; a parameter adjustment value setting step, setting an adjustment value for a plasma adjustment medium parameter based on the geometric contour of the baffle unit; a parameter adjustment step, adjusting one or more of the size of the exhaust port of the upper baffle of the baffle unit and the height of the upper baffle according to the adjustment value of the plasma adjustment medium parameter; and a plasma density adjustment step, adjusting the plasma density distribution in the process space of the substrate processing apparatus by adjusting the plasma adjustment medium parameter.

[0024] As an example, the parameter adjustment step could be to adjust the height of the upper baffle by lowering the upper baffle based on the edge ring of the substrate support unit.

[0025] As an example, the parameter adjustment step could be to select a descent height within a range of less than 40mm by lowering the upper baffle based on the edge ring of the substrate support unit.

[0026] As an example, the parameter adjustment step may involve adjusting the size of the exhaust port of the upper baffle through the exhaust port adjustment component of the baffle unit.

[0027] As an example, the parameter adjustment step could be to adjust the size of the exhaust port of the upper baffle to a diameter selected within a range of less than 10 mm.

[0028] As an example, the parameter adjustment step could be to adjust the height of the upper baffle while keeping the size of the exhaust port of the upper baffle fixed.

[0029] As an example, the plasma density control method may further include an exhaust step, in which gas is exhausted through the upper baffle and a lower baffle located below the upper baffle.

[0030] As an example, the adjustment value of the plasma adjustment medium parameter may be pre-stored based on the geometric contour of the baffle unit corresponding to the required plasma density distribution, and the adjustment value of the plasma adjustment medium parameter may be pre-stored based on the geometric contour of the baffle unit.

[0031] A preferred embodiment of the substrate processing apparatus according to the present invention includes: a cavity providing a process space; a substrate support unit disposed in the process space, on which a substrate is placed and supported, and including an edge ring mounted on the outer contour of the substrate; and a baffle unit disposed around the substrate support unit to exhaust gas from the process space, and including an upper baffle, a lower baffle, an exhaust port adjustment member, an upper baffle lifting part, and an exhaust member, wherein the upper baffle is an annular plate with exhaust ports and is capable of being lifted and lowered, the lower baffle is an annular plate without exhaust ports and is located below the upper baffle, and the exhaust port adjustment member adjusts the size of the exhaust ports of the upper baffle. The upper baffle lifting unit raises and lowers the upper baffle, and the exhaust member discharges gas through the upper baffle and the lower baffle; and the control unit adjusts the plasma density distribution by using the size of the exhaust hole of the upper baffle and the height resulting from the descent of the upper baffle relative to the edge ring as plasma adjustment medium parameters according to the required plasma density distribution, and controls the size of the exhaust hole and the height of the upper baffle such that the diameter of the exhaust hole of the upper baffle is selected in the range of less than 10 mm, and the height of the upper baffle is the descent height selected in the range of less than 40 mm relative to the edge ring of the substrate support unit.

[0032] According to this invention, the geometry of the shielding baffle can be applied to adjust the parameters of the plasma adjustment medium to uniformly or precisely control the plasma density distribution in each region.

[0033] Furthermore, it can solve the problem of contamination of the entire equipment and a decrease in process yield caused by foreign matter such as polymers spreading from areas that are not in the process area to the process area when gas is discharged through the baffle unit.

[0034] Furthermore, structural asymmetry can be addressed by using louvers that contact the padding as the lower baffle rises and falls, thereby providing a path for the substrate to be introduced and removed.

[0035] In addition, heat conduction can be achieved by physical contact between the upper baffle and the temperature-adjustable pad with heating components, thereby adjusting the temperature of the upper baffle and resolving thermal asymmetry that may occur in the process area.

[0036] The effects of the present invention are not limited to those mentioned above. Other effects not mentioned can be clearly understood by those skilled in the art from the following description. Attached Figure Description

[0037] Figure 1 An embodiment of the substrate processing apparatus according to the present invention is shown.

[0038] Figure 2 An embodiment of a shielding baffle unit in a substrate processing apparatus according to the present invention is shown.

[0039] Figures 3 to 6 Various embodiments are shown in which the size of the vent hole is adjusted by a vent hole adjustment member in a substrate processing apparatus according to the invention.

[0040] Figures 7 to 9 A working diagram is shown regarding an embodiment of a substrate processing apparatus according to the present invention.

[0041] Figure 10 An embodiment of the lower baffle of the substrate processing apparatus according to the present invention is shown.

[0042] Figure 11 A working diagram is shown showing the adjustment of the geometry of a baffle unit in a substrate processing apparatus according to the present invention.

[0043] Figure 12 An example is shown of using the geometry of the baffle unit of the substrate processing apparatus according to the invention as an element setting for plasma adjustment medium parameters.

[0044] Figure 13 as well as Figure 14 An example of a plasma field depending on the presence or absence of a shielding baffle is shown.

[0045] Figure 15 The correlation between the input and dependent variables is shown by the Pearson correlation matrix obtained from experiments related to the present invention.

[0046] Figure 16 The relationship between the input variables and the average plasma electron density is shown through the dispersion analysis (ANOVA) of this invention.

[0047] Figure 17 Additional analytical results are shown regarding the interaction effects between plasma adjustment medium parameter elements in this invention.

[0048] Figure 18 A flowchart is shown regarding an embodiment of the plasma density control method according to the present invention.

[0049] (Explanation of reference numerals in the attached diagram)

[0050] 10: Substrate processing apparatus

[0051] 100: Cavity

[0052] 200: Substrate support unit

[0053] 300: Gas Supply Unit

[0054] 400: Plasma Generation Unit

[0055] 500: Baffle unit

[0056] 510: Upper baffle

[0057] 512: Exhaust port

[0058] 530: Lower baffle

[0059] 540: Upper baffle lifting section

[0060] 550: Exhaust components

[0061] 700: Control Department Detailed Implementation

[0062] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, but the present invention is not limited or restricted by the embodiments.

[0063] To illustrate the present invention, its advantages in operation, and the objectives achieved through its implementation, preferred embodiments of the present invention are described below for observation.

[0064] First, the terminology used in this application is for illustrative purposes only and is not intended to limit the invention. Unless explicitly stated otherwise in the context, singular expressions may include plural expressions. Furthermore, in this application, terms such as "comprising" or "having" should be understood as specifying the presence of features, numbers, steps, operations, constituent elements, accessories, or combinations thereof described in the specification, and do not preclude the presence or additional possibilities of one or more other features or numbers, steps, operations, constituent elements, accessories, or combinations thereof.

[0065] In describing this invention, detailed descriptions of related well-known structures or functions are omitted where it is determined that such detailed descriptions would unnecessarily obscure the spirit of the invention.

[0066] Screen baffles, as structures that delineate the plasma discharge region, can form an equipotential line with the reaction chamber, thus shielding the diffusion of plasma. In particular, screen baffles can also serve as structures that separate the plasma processing area from the exhaust area.

[0067] Recently, in CCP (Capacitively Coupled Plasma) substrate processing apparatuses, devices are being designed with narrower electrode spacing to improve productivity and process uniformity. By employing this structure, the plasma discharge space volume is reduced, potentially allowing plasma to diffuse into the exhaust region. This plasma diffusion into the exhaust region can hinder the uniformity of plasma density across the process area.

[0068] Furthermore, the shielding effect of the baffle may also affect the residence time of process byproducts and etching gases on the wafer surface, thus potentially increasing the baffle's role.

[0069] In this invention, by applying a specific geometry to the shielding baffle, the diffused plasma is shielded by the baffle, thereby controlling the plasma distribution. That is, in this invention, the geometry of the shielding baffle can be applied to adjust the plasma medium parameters to control the plasma distribution.

[0070] More specifically, this invention proposes a technique for precisely controlling plasma density distribution by selecting and adjusting the exhaust port size and the height of the shielding baffle as parameters of the plasma adjustment medium.

[0071] Figure 1 An embodiment of the substrate processing apparatus according to the present invention is shown. Figure 2 An embodiment of a shielding baffle unit in a substrate processing apparatus according to the present invention is shown.

[0072] The substrate processing apparatus 10 may include a cavity 100, a substrate support unit 200, a gas supply unit 300, a plasma generation unit 400, a baffle unit 500, a control unit 700, etc.

[0073] The cavity 100 can provide a process space for performing processes inside. As an example, the cavity 100 can be provided from a cylindrical metal material.

[0074] A through passage 160 can be formed on one side wall of the cavity 100. The through passage 160 can serve as a passage for moving the substrate in or out. The through passage 160 can be opened and closed by a door 180 provided on the outer side wall of the cavity 100.

[0075] The substrate support unit 200 can be disposed inside the cavity 100 to support the substrate W to be processed, such as a wafer. As an example, the substrate support unit 200 can be provided as an electrostatic chuck that uses electrostatic force to attract the substrate. As another example, the substrate support unit 200 can support the substrate by various means such as mechanical clamping.

[0076] The substrate support unit 200 may include a dielectric plate 210, a ring assembly 250, a substrate 230, etc.

[0077] The substrate W can be directly placed on the dielectric plate 210. The dielectric plate 210 can be provided in a disk shape to correspond to the wafer shape. Inside the dielectric plate 210, there can be chuck electrodes 211 that receive power from the chuck power supply 215 and attract the substrate W by electrostatic force, and heaters 212 that heat the substrate W. The heater 212 can keep the substrate W at the process temperature during the process. Depending on the situation, when the substrate W is held by mechanical clamping, the chuck power supply 215 and chuck electrodes 211 can be omitted. In addition, the heater 212 can also be omitted.

[0078] The ring assembly 250 may include a focusing ring 252 and an edge ring 254. The focusing ring 252 can concentrate plasma toward the substrate W. The focusing ring 252 can be provided as a periphery surrounding the dielectric plate 210. The focusing ring 252 can be provided as a ring shape. The edge ring 254 can be provided as a ring surrounding the focusing ring 252. Since the ring assembly 250 is configured to surround the substrate W, plasma ions can be uniformly and perpendicularly incident toward the center and periphery of the substrate W.

[0079] In this embodiment, the ring assembly 250 is shown and described as including a focusing ring 252 and an edge ring 254, but it is not limited thereto. The ring assembly 250 may also be configured as a single outer ring or multiple outer rings combined with each other.

[0080] The substrate 230 can support the dielectric plate 210. The substrate 230 can be located below the dielectric plate 210 and is fixedly bonded to the dielectric plate 210 by means of an bonding layer (not shown).

[0081] The substrate 230 may include a conductive material. For example, the material of the substrate 230 may include aluminum. The substrate 230 may be electrically connected to the lower power supply 440 and receive high-frequency power from the lower power supply 440. The substrate 230 may function as an electrode for generating an electric field and may function as the lower electrode of the plasma generation unit 400. However, it is not limited to this; the substrate 230 may also be grounded to function as a lower electrode.

[0082] The substrate 230 may have a stepped shape on its upper surface, such that its central region is higher than its edge regions. The central region of the substrate 230 may correspond to the bottom surface of the dielectric plate 210. A cooling flow path 232 may be formed inside the substrate 230. The cooling flow path 232 provides a pathway for the circulation of cooling fluid. The cooling fluid can maintain the substrate W at the process temperature during flow through the cooling flow path 232. The cooling flow path 232 may be provided both inside the substrate 230 and selectively extending to the dielectric plate 210.

[0083] The gas supply unit 300 supplies process gas to the interior of the cavity 100. The gas supply unit 300 may include a gas storage unit 310, a gas supply line 330, and a gas regulating valve 350. The gas supply line 330 supplies process gas from the gas storage unit 310 to the interior of the cavity 100. The gas regulating valve 350 regulates the supply quantity and supply rate of the process gas supplied through the gas supply line 330.

[0084] The plasma generation unit 400 can excite the process gas supplied to the cavity 100 into a plasma state. The plasma generation unit 400 can form plasma within the internal space of the cavity 100. For example, the plasma generation unit 400 can use a capacitively coupled plasma (CCP) source to form plasma. Alternatively, the plasma generation unit 400 can also use an inductively coupled plasma (ICP) source to form plasma.

[0085] The plasma generation unit 400 may optionally include an upper electrode 410, an upper power supply 420, and a lower power supply 440. The upper electrode 410 may be arranged vertically opposite to the substrate 230, which acts as the lower electrode. The electrodes and power supply of the plasma generation unit 400 may be appropriately modified in form and position according to the CCP or ICP type.

[0086] Nozzle 130 can receive process gas from gas supply unit 300. Injection hole 131 can be formed in nozzle 130, through which process gas diffuses into process space of cavity 100.

[0087] As an example, the upper electrode 410 can also be configured on the nozzle 130.

[0088] The baffle unit 500 allows gas to escape from the process space of the cavity 100. In particular, the baffle unit 500, as a structure separating the plasma process area and the gas exhaust area, can perform a plasma shielding function.

[0089] The baffle unit 500 may include an upper baffle 510, a lower baffle 530, an upper baffle lifting part 540, an exhaust component 550, etc.

[0090] The upper baffle 510 can be located around the substrate support unit 200 and can be positioned above the lower baffle 530 in terms of cross-sectional angle. The upper baffle 510 can be configured as an annular plate surrounding the periphery of the substrate support unit 200. Vent holes 512 can be formed in the upper baffle 510.

[0091] In describing one embodiment of the present invention, the vent 512 is shown as a circular hole to adjust the diameter of the circular hole during the explanation. However, this is only one embodiment, and the vent 512 can be adapted to various forms other than a circular hole. For example, the vent hole can also be adapted to be a polygonal hole or a slit.

[0092] In the Figure 2 In the middle, the exhaust holes 512 are arranged in two rows on the upper baffle 510. Depending on the situation, the number and arrangement of the exhaust holes 512 can be varied.

[0093] In particular, the diameter of the vent hole 512 of the upper baffle 510 can be changed according to the process conditions. The diameter of the vent hole 512 of the upper baffle 510 can be selected in the range of less than 10 mm. Preferably, the diameter of the vent hole 512 can be selected in the range of 5 to 10 mm.

[0094] In this invention, the exhaust port 512 is used as one of the parameters of the plasma adjustment medium, and the size of the exhaust port 512 is adjusted to control the plasma density, which will be explained in detail through the following embodiments.

[0095] As an example, an upper baffle 510 with a fixed diameter matching the exhaust port 512 can be installed on the baffle unit 500 according to the required process conditions.

[0096] As another example, the diameter of the vent hole 512 of the upper baffle 510 can be varied depending on the required process conditions.

[0097] Related to this, Figures 3 to 6 Various embodiments are shown in which the size of the vent hole is adjusted by a vent hole adjustment member in a substrate processing apparatus according to the invention.

[0098] As an example, the exhaust port adjustment component is as described above. Figure 3 It may include an exhaust port adjusting nozzle 515, which adjusts the size of the exhaust port 512 of the upper baffle 510.

[0099] As described Figure 3(a) When the diameter of the exhaust port 512 of the upper baffle 510 is D1, as described Figure 3 (b) can be achieved by installing an exhaust port adjustment nozzle 515 on the exhaust port 512 to adjust the diameter of the exhaust port 512 to D2.

[0100] For example, the diameter D1 of the exhaust hole 512 of the upper baffle 510 is set to 10mm, and the diameter D2 of the exhaust hole adjusting nozzle 515 is varied from 5mm to less than 10mm. The corresponding exhaust hole adjusting nozzle 515 is installed on the exhaust hole 512 of the upper baffle 510 according to the required diameter.

[0101] As another example, the exhaust port adjustment component is as described above. Figure 4 It may include an exhaust port adjustment plate 517, which adjusts the size of the exhaust port 512 of the upper baffle 510.

[0102] The exhaust port adjusting plate 517 may have a protruding adjusting protrusion 518, which can be inserted into a plurality of exhaust ports 512 provided on the upper baffle 510. Alternatively, the adjusting protrusion 518 may have a hole 519 with a diameter D2, and the exhaust port adjusting plate 517 may be mounted on the upper baffle 510 and matched with the exhaust ports 512 of the upper baffle 510 to insert the adjusting protrusion 518.

[0103] As another example, the diameter D1 of the exhaust hole 512 of the upper baffle 510 is set to 10mm, and various exhaust hole adjustment plates 517 with the diameter D2 of the adjustment protrusion 518 ranging from 5mm to less than 10mm are provided. The exhaust hole adjustment plate 517 is installed on the upper baffle 510 according to the required diameter.

[0104] As yet another example, the exhaust port adjustment component is as described above. Figure 5 as well as Figure 6 It may include an exhaust port adjustment unit 520, which adjusts the size of the exhaust port 512 of the upper baffle 510.

[0105] The exhaust port adjustment unit 520 may include an adjustment blade 521, a rotating ring 525, a rotating component 527, a driver (not shown), etc.

[0106] Adjusting blades 521 can be installed around the vent hole 512. Multiple adjusting blades 521 can be arranged at equal intervals along the circumference of the vent hole 512. Each adjusting blade 521 may have a protruding shaft 523. The protruding shaft 523 can be fixed to the upper baffle 510 at one end and rotated while being held in a fixed position by the upper baffle 510.

[0107] The rotating ring 525 can be configured to abut against the inner surface of each of the protruding shafts 523 of the plurality of adjusting blades 521. As an example, the inner surface of the rotating ring 525 can be formed of a material with a certain level of friction coefficient. The rotating ring 525 can abut against each of the protruding shafts 523 and cause the protruding shafts 523 to rotate by friction.

[0108] The rotating ring 525 can be rotated by the rotating member 527. As an example, the concave and convex portions can be alternately formed in the form of serrations on the outer surface of the rotating ring 525 and the inner surface of the rotating member 527, with the serrations on the outer surface of the rotating ring 525 and the serrations on the inner surface of the rotating member 527 meshing with each other.

[0109] The rotating component 527 can be rotated by a driver (not shown). As an example, the driver (not shown) can be a stepper motor or the like, and the rotation angle can be precisely adjusted.

[0110] The rotating component 527 can rotate the rotating ring 525. While the protruding shaft 523 of each adjusting blade 521 rotates with the rotation of the rotating ring 525, each adjusting blade 521 rotates in the rotation direction of each protruding shaft 523.

[0111] As each adjusting blade 521 rotates, the size of the exhaust hole 512 formed by each adjusting blade 523 can be changed.

[0112] If, as described Figure 6 (a) allows the rotating ring 525 to rotate clockwise while the rotating component 527 rotates clockwise. As the rotating ring 525 rotates, the protruding shaft 523 of the adjusting blade 521 rotates, and the ends of each adjusting blade 521 converge towards the center of the exhaust port 512. This reduces the diameter of the exhaust port 512 to D3.

[0113] Conversely, as described Figure 6 (b) When the rotating component 527 rotates counterclockwise, the ends of each adjusting blade 521 move away from the center of the exhaust port 512. As a result, the diameter of the exhaust port 512 can be expanded to D4.

[0114] The vent adjustment component can be modified in various ways. For example, it can be configured as a louver that moves linearly toward the center of the vent to adjust the size of the vent.

[0115] Back to Figure 1 as well as Figure 2 Continue to observe baffle unit 500.

[0116] The upper baffle 510 can be raised or lowered via the upper baffle lifting part 540. Thus, the height of the upper baffle 510 can be adjusted by lowering or raising it to the height of the edge ring 254, based on the height of the edge ring 254.

[0117] Multiple upper baffle lifting units 540 can be provided, and include various components capable of linear reciprocating drive, such as linear motors and hydraulic pistons. As an example, the upper baffle lifting unit 540 may include a shaft 541 with one end connected to the upper baffle 510 and the other end connected to a drive unit 545, and a drive unit 545 that causes the shaft 541 to reciprocate linearly. Multiple shafts 541 can be connected to the center of the upper baffle 510 in the width direction to support the upper baffle 510. The upper baffle lifting unit 540 can raise and lower the upper baffle 510 while supporting its center in the width direction, thereby ensuring a balanced center of gravity and smooth raising and lowering of the upper baffle 510.

[0118] The lower baffle 530 can be located below the upper baffle 510. No vent hole may be formed in the lower baffle 530. The lower baffle 530 can be fixed in position. Multiple through holes 535 can be provided at the center of the lower baffle 530 in the width direction. The through holes 535 can support the movement of the shaft 541 of the upper baffle lifting part 540.

[0119] As an example, the lower baffle 530 can be configured as an annular plate with a larger inner diameter and a smaller outer diameter compared to the upper baffle 510.

[0120] If the lower baffle 530 is positioned on the same line below the upper baffle 510, a gas flow space can be formed on the inner and outer sides of the lower baffle 530.

[0121] The baffle unit 500 may include an exhaust member 550 disposed at the lower end of the cavity 100. The exhaust member 550 can discharge gases and byproducts in the process space of the cavity 100 through the upper baffle 510 and the lower baffle 530.

[0122] Alternatively, the exhaust pipe 551 of the exhaust component 550 can be connected to the lower end of the cavity 100, and the exhaust pump 555 of the exhaust component 550 can be disposed on the exhaust pipe 551 to provide suction.

[0123] Figures 7 to 9 A working diagram is shown regarding an embodiment of a substrate processing apparatus according to the present invention.

[0124] As described Figure 7 as well as Figure 8 As shown, the gas and byproducts in the process space of the cavity 100 can be discharged downward through the exhaust port 512 of the upper baffle 510 and the gas flow space provided on the inner and outer sides of the lower baffle 530 at the height where the upper baffle 510 and the lower baffle 530 are separated.

[0125] The exhaust pump 555 of the exhaust component 550 can discharge gas and byproducts to the outside through the exhaust pipe 551. As described Figure 9 As shown, when the upper baffle 510 descends to a height where it contacts the lower baffle 530, the connection between the process space and the lower space of the lower baffle 530 can be blocked. That is, the exhaust port 512 of the upper baffle 510 can be blocked by the lower baffle 530, thereby blocking the connection between the process space and the lower space through the upper baffle 510 and the lower baffle 530.

[0126] Therefore, it can prevent foreign matter such as gas and by-products existing in the lower space of the lower baffle 530 from flowing back into the process space and scattering.

[0127] Furthermore, in order to prevent the inner wall of the cavity 100 from being exposed to plasma, a liner 150 can be provided on the inner sidewall of the cavity 100.

[0128] The pad 150 may include an upper pad 151 and a lower pad 155.

[0129] The upper liner 151 can be fixedly installed as a cylinder on the upper end of the inner side wall of the cavity 100.

[0130] The lower liner 155 can be connected at its lower end to the outside of the upper baffle 510.

[0131] As an example, the lower liner 155 can be cylindrical with its lower end connected to the outer side of the annular plate of the upper baffle 510.

[0132] A heating element 157 may be provided in the lower liner 155. As an example, a coil may be built into the lower liner 155 as the heating element 157, and the temperature may be raised by applying power.

[0133] The upper baffle 510 can physically contact the lower liner 155 to achieve heat conduction. The heating temperature of the lower liner 155 can be transferred to the upper baffle 510 to regulate the temperature of the upper baffle 510.

[0134] The thermal asymmetry that may occur in the process zone can be resolved by adjusting the temperature of the upper baffle 510.

[0135] When the upper baffle 510 rises, the lower liner 155 can also rise together.

[0136] In one embodiment of the invention, during process execution, the upper baffle 510 can be set to 0 mm based on the height of the edge ring 254, and raised or lowered to a height selected within a range of -40 mm downwards. The size of the liner 150 can be determined accordingly.

[0137] If, the stated Figure 7The diagram shows the upper baffle 510 lowered to -40mm with the height of the edge ring 254 as a reference. At this point, the through passage 160 located on one side wall of the cavity 100 needs to be closed by the gasket 150. That is, the size of the gasket 150 can be determined such that, when the upper baffle 510 is lowered to -40mm during the process, the through passage 160 located on one side wall of the cavity 100 can be closed by the lower gasket 155.

[0138] Additionally, when the upper baffle 510 is raised to the height of the edge ring 254, as Figure 8 The lower pad 155 rises together, and the configuration of the lower pad 155 can be adjusted so that the upper pad 151 and the lower pad 155 do not interfere with each other and the outer side of the lower pad 155 can abut against the inner side of the upper pad 151.

[0139] In this invention, the height of the upper baffle 510 is used as a reference, with the height of the edge ring 254 as a reference, to control the plasma density as one of the plasma adjustment medium parameters, which will be explained in detail through the following embodiments. Furthermore, the liner 150 can function as a louver to open and close the through passage 160 disposed on one side wall of the cavity 100 and the process space.

[0140] As an example, refer to the above Figures 7 to 9 The upper liner 151 can be disposed on the inner side wall of the cavity 100 above the through passage 160.

[0141] As described Figure 9 The lower liner 155 can have a height that allows the passageway 160 to be fully open during maximum descent. Additionally, as described... Figure 7 as well as Figure 8 Alternatively, when the lower liner 155 rises, the passageway 160 closes, and the inner wall of the cavity 100 is shielded by the lower liner 155 and the upper liner 151. In this way, the liner 150 can act as a louver to open and close the passageway 160 while protecting the inner wall of the cavity 100 from exposure to plasma.

[0142] Furthermore, by using a liner that acts as a louver as the lower baffle rises and falls, structural asymmetry can be addressed while providing pathways for the introduction and exit of the substrate.

[0143] In the previously observed embodiments, the lower baffle 530 is shown and described as being fixed, but unlike this, the lower baffle 530 can also be raised and lowered.

[0144] Figure 10 An embodiment of the lower baffle of the substrate processing apparatus according to the present invention is shown.

[0145] The lower baffle 530 can be divided into multiple parts, and is composed of lower baffle plates 530a, 530b, 530c and 530d corresponding to these multiple parts.

[0146] Each of the lower baffle plates 530a, 530b, 530c, and 530d can be equipped with a lower baffle lifting part 560 to allow each lower baffle plate 530a, 530b, 530c, and 530d to rise and fall independently. As an example, the lower baffle lifting part 560 may include a shaft 561 with one end connected to the lower baffle 530 and the other end connected to a drive part 565, and a drive part 565 for linear reciprocating motion of the shaft 561.

[0147] Depending on the process conditions, the directionality of the process result can be changed by individually raising and lowering the lower baffle plates 530a, 530b, 530c, and 530d according to each part of the lower baffle 530.

[0148] The control unit 700 can control the overall operation of the substrate processing apparatus 10. In particular, the control unit 700 can control the operation of the baffle unit 500 to control the plasma density distribution.

[0149] As an example, the control unit 700 can use the exhaust hole size and the height of the upper baffle 510 of the baffle unit 500 as plasma adjustment medium parameters to control the plasma density distribution.

[0150] Figure 11 A working diagram is shown showing the adjustment of the geometry of a baffle unit in a substrate processing apparatus according to the present invention.

[0151] In this invention, the size D of the exhaust hole 512 of the upper baffle 510 can be adjusted, and the height H of the upper baffle 510 can be adjusted based on the height of the edge ring 254.

[0152] Referring to the above Figure 11 (a) The upper baffle 510 can be raised to a position close to the edge ring 254 via the upper baffle lifting part 540. (Refer to the above description) Figure 11 (b) The upper baffle 510 can be lowered to a position H lower than the edge ring 254 via the upper baffle lifting part 540. The size (diameter: D) of the exhaust port 512, the height H of the exhaust port 512, and the dielectric constant P of the upper baffle 510 can be used as plasma adjustment medium parameters.

[0153] Figure 12 An example is shown of using the geometry of the baffle unit of the substrate processing apparatus according to the invention as an element setting for plasma adjustment medium parameters.

[0154] Based on the above Figure 12In order to apply the geometry of the shielding baffle as a plasma process tuning parameter, experiments were conducted on the dry etching process of the substrate processing device.

[0155] As a 300mm wafer etching processing equipment, according to the above... Figure 12 The substrate processing apparatus of the present invention performs a simulation of plasma distribution based on the presence or absence of baffle units.

[0156] A CCP-type substrate processing apparatus is used, which grounds the upper electrode and applies frequency power to the lower electrode. Furthermore, a consumable ring structure is used as a ring assembly in the edge region where the lower electrode of the wafer is located for process control, and isothermal conditions are applied to the walls of the cavity to ground and facilitate heat transfer.

[0157] First, the plasma distribution based on the presence or absence of the shielding baffle was confirmed. Figure 13 as well as Figure 14 An example of a plasma field depending on the presence or absence of a shielding baffle is shown.

[0158] The Figure 13 (a) shows the plasma distribution when no shielding baffle is applied. Figure 13 (b) shows the plasma distribution when a shielding baffle is applied.

[0159] As described Figure 13 As shown, the overall plasma shape changes depending on the presence or absence of the shielding baffle. Therefore, the baffle can function as a plasma process tunable parameter by simultaneously dividing the process region while controlling the internal pressure of the cavity and the diffusion of process byproducts.

[0160] The Figure 14 Shown in the Figure 13 The X and Y axes are used as references to determine the time-averaged plasma electron density distribution based on the presence or absence of shielding baffles. The X and Y axes refer to the horizontal and vertical directions at the cross-sectional angle of cavity 100, respectively.

[0161] The Figure 14 Figure (a) shows the plasma distribution along the X-axis, revealing a significant difference in plasma distribution depending on the presence or absence of a shield. It can be observed that without a shield, the plasma density diffuses outwards, but with a shield, the plasma density does not diffuse outwards and instead converges towards the center. This effect demonstrates the displacement of the plasma density towards the center of the discharge region.

[0162] In addition, the Figure 14 (b) shows the plasma distribution along the Y-axis, confirming that when a shielding baffle is applied, the plasma above the shielding baffle is effectively shielded.

[0163] Based on these experimental results, it can be confirmed that the overall plasma shape changes depending on the presence or absence of a shielding baffle. That is, it can be seen that the application of a shielding baffle affects plasma diffusion and alters the plasma density distribution along both the X and Y axes. Therefore, in this invention, the geometry of the shielding baffle is adjusted to more precisely and finely control the plasma distribution.

[0164] In particular, in this invention, the diameter of the exhaust port of the upper baffle and the height of the upper baffle can be set as plasma adjustment medium parameters as a geometric change of the shielding baffle, and these parameters can be adjusted to shape the plasma distribution.

[0165] To identify significant factors related to plasma conditioning medium parameters, three factors were selected as plasma conditioning medium parameters: the diameter of the exhaust port, the height of the upper baffle, and the permittivity of the baffle. The influence of each parameter on the plasma electron density was analyzed.

[0166] For the purpose of the experiment, as parameters for adjusting the plasma medium, the diameter of the exhaust port, the height of the upper baffle, and the permittivity of the baffle were combined as parameters, and five levels were selected as shown in Table 1 below.

[0167] Based on Table 1 below, an orthogonal array table was constructed, and experimental simulations were performed based on it.

[0168] Table 1

[0169] level Height (mm) Hole width (mm) Dielectricity 1 -10 5 Ground (0V) 2 -17.5 10 2 3 -25 15 6 4 -32.5 20 10 5 -40 25 13

[0170] The five levels in Table 1 are uniformly distributed based on the minimum and maximum values ​​that can be specified within the geometry. Here, the aperture width represents the value specified in the table. Figure 12 The width D of the exhaust port of the upper baffle varies along the X-axis, and the height represents the distance relative to the width D of the exhaust port of the upper baffle. Figure 12 The dielectric constant is expressed as the Y-axis distance of the height H position of the baffle, with the edge ring as the reference. Figure 12 The dielectric constant P of the upper baffle. To account for the interactions between the parameter elements, 125 examples were analyzed.

[0171] To analyze the impact of three variables related to plasma adjustment medium parameters on plasma electron density, Pearson correlation matrix and ANOVA were used.

[0172] Figure 15 The correlations between the input and dependent variables are shown by the Pearson correlation matrix based on this experiment.

[0173] The strongest correlation is the width D of the hole, followed by the height H of the upper baffle.

[0174] To conduct a more comprehensive evaluation of factors such as the orifice width D, baffle height H, and dielectric constant P, the principal effects and interaction effects were analyzed using dispersion analysis (ANOVA).

[0175] Figure 16 The relationship between the input variables and the average plasma electron density is shown through dispersion analysis (ANOVA).

[0176] The Figure 16 Figure (a) shows the correlation between height H and plasma electron density. It can be seen that within the range of -10 to -40 mm of height H, the average plasma electron density increases or decreases with variations in height H. Here, the - symbol indicates how much the upper baffle 510 has decreased compared to the height of the edge ring 254. Based on these results, it can be concluded that the height H of the shielding baffle affects the exhaust efficiency, which is also related to the inflow gas velocity and the number and size of the orifices.

[0177] The Figure 16 (b) shows the correlation between dielectric constant P and plasma electron density. It can be seen that the lines of the curve representing the average plasma electron density are closely aligned and show a slope close to 0, which indicates that the correlation of dielectric constant is not high.

[0178] The Figure 16 (c) shows the correlation between the aperture width D and the plasma electron density, and it can be seen that the aperture width D exhibits high strength in the range of 5 to 10 mm.

[0179] Based on these results, when each input variable is considered independently, it can be confirmed that the height H and the width D of the aperture are highly correlated with the plasma electron density.

[0180] Figure 17 Additional analytical results regarding the interaction effects between plasma-adjusted medium parameter elements are presented.

[0181] The Figure 17(a) shows the correlation between the dielectric constant P and the height H with respect to the average plasma electron density. There is no large change in the slope, so it can be confirmed that the interaction between dielectric constant P and height H is not significant.

[0182] The Figure 17 (b) shows the correlation between the simultaneous effects of the aperture width D and height H with respect to the average plasma electron density. Figure 17 (c) shows the correlation between the aperture width D and the dielectric constant P with respect to the average plasma electron density. It can be seen that the aperture width D exhibits high sensitivity in the range of 5–10 mm.

[0183] According to the experiments conducted by the applicant, it was confirmed that the width D of the aperture is less than 10 mm, and the plasma uniformity improves as the height H increases towards -40 mm.

[0184] Taking into account these experimental results, it can be confirmed that the plasma density can be controlled by adjusting the width D and height H of the aperture, which are parameters of the plasma adjustment medium.

[0185] Furthermore, this invention proposes a plasma density control method in the substrate processing apparatus according to the invention as observed above.

[0186] Related to this, Figure 18 A flowchart illustrating an embodiment of the plasma density control method according to the present invention is shown. The plasma density control method according to the present invention is implemented by the substrate processing apparatus according to the present invention described above; therefore, the embodiment of the substrate processing apparatus described above will also be referred to.

[0187] The control unit 700 confirms the geometric profile of the baffle unit 500 that corresponds to the plasma density distribution required in the corresponding plasma process (S110).

[0188] The plasma density of different regions of the substrate needs to be formed differently or uniformly throughout the substrate according to each process. The plasma density conditions corresponding to such processes can be matched according to each process.

[0189] Furthermore, as explained above, the plasma density can be adjusted according to the geometry of the baffle unit 500. The control unit 700 can pre-store the outline of the geometry of the baffle unit according to the plasma density required by each process, and confirm the geometry corresponding to the corresponding process in the stored outline.

[0190] The control unit 700 can set adjustment values ​​for plasma adjustment medium parameters corresponding to the geometric contour of the baffle unit 500 (S130). The control unit 700 can store adjustment values ​​for plasma adjustment medium parameters in advance based on the geometric contour of the baffle unit 500. For example, adjustment values ​​for any one or more elements, such as the size of the exhaust port 512 of the upper baffle 510 and the height of the upper baffle 510, can be set as elements of the plasma adjustment medium parameters corresponding to a specific geometric contour of the baffle unit 500.

[0191] The control unit 700 can adjust the size of the exhaust port 512 of the upper baffle 510 and the height of the upper baffle 510 as elements of the plasma adjustment medium parameters (S150).

[0192] As an example, the control unit 700 can adjust the height of the upper baffle 510 by lowering the upper baffle 510 to an adjustable height, with the edge ring 254 of the substrate support unit 200 as a reference.

[0193] Preferably, as described above, the upper baffle 510 can be lowered to a height selected within the range of 40 mm or less, with the edge ring 254 of the substrate support unit 200 as a reference.

[0194] As an example, the control unit 700 can adjust the size of the exhaust hole 512 of the upper baffle 510 by matching the adjustment value with the exhaust hole adjustment unit 520 of the baffle unit 500.

[0195] Preferably, as described above, the size of the vent hole 512 of the upper baffle 510 can be adjusted to a diameter selected within the range of 10 mm or less. More preferably, the size of the vent hole 512 of the upper baffle 510 can be adjusted to a diameter selected within the range of 5 to 10 mm.

[0196] The control unit 700 can adjust the height of the upper baffle 510 while the size of the exhaust hole 512 of the upper baffle 510 is fixed, or adjust the size of the exhaust hole 512 of the upper baffle 510 while the height of the upper baffle 510 is fixed.

[0197] More preferably, the control unit 700 can also simultaneously adjust the size of the exhaust port 512 of the upper baffle 510 and the height of the upper baffle 510.

[0198] The plasma density distribution can be adjusted by regulating various elements of the plasma adjustment medium parameters to match the required process conditions (S170).

[0199] Furthermore, the process of controlling the exhaust component 550 to discharge gases and byproducts from the process space through the baffle unit 500 can also be performed simultaneously with the execution of the process.

[0200] According to this invention, the geometry of the shielding baffle can be applied to adjust the parameters of the plasma adjustment medium to uniformly or precisely control the plasma density distribution in each region.

[0201] 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 are included within the scope of the claims.

Claims

1. A substrate processing apparatus, characterized in that, include: The cavity provides space for the process; A substrate support unit is disposed in the process space and on which a substrate is placed and supported, and includes an edge ring mounted on the outer contour of the substrate; A baffle unit, disposed around the periphery of the base plate support unit, includes an upper baffle, a lower baffle, and an upper baffle lifting part. The upper baffle has an exhaust hole and is movable. The lower baffle is located below the upper baffle. The upper baffle lifting part causes the upper baffle to move up and down. The control unit uses the exhaust port of the upper baffle and the height caused by the raising and lowering of the upper baffle as plasma adjustment medium parameters to adjust the plasma density distribution.

2. The substrate processing apparatus according to claim 1, characterized in that, The upper baffle is an annular plate with the exhaust port. The lower baffle is an annular plate without exhaust holes.

3. The substrate processing apparatus according to claim 1, characterized in that, The control unit adjusts the height of the upper baffle by lowering the upper baffle based on the height of the edge ring.

4. The substrate processing apparatus according to claim 1, characterized in that, The baffle unit further includes: An exhaust port adjustment component is used to adjust the size of the exhaust port on the upper baffle.

5. The substrate processing apparatus according to claim 1, characterized in that, The control unit adjusts one or more of the size of the exhaust port and the height of the upper baffle according to the required plasma density distribution.

6. The substrate processing apparatus according to claim 1, characterized in that, The control unit adjusts the height of the upper baffle according to the required plasma density distribution while the size of the exhaust port is fixed.

7. The substrate processing apparatus according to claim 1, characterized in that, Select the diameter of the exhaust hole of the upper baffle within a range of less than 10mm.

8. The substrate processing apparatus according to claim 1, characterized in that, The height of the upper baffle is a downward height selected within a range of less than 40mm, based on the edge ring of the substrate support unit.

9. The substrate processing apparatus according to claim 1, characterized in that, The baffle unit further includes: The exhaust component discharges gas through the upper baffle and the lower baffle.

10. The substrate processing apparatus according to claim 9, characterized in that, The baffle unit is formed by the upper baffle contacting the lower baffle to block the process space from the space below the lower baffle.

11. The substrate processing apparatus according to claim 1, characterized in that, The cavity has a through passage on one side wall. The cavity also includes: A door, corresponding to the passageway of the cavity, that selectively opens or closes the passageway; and The gasket is in contact with or adjacent to the inner wall of the cavity. The gasket includes: An upper liner is disposed above the through passage on the inner sidewall of the cavity; and The lower liner is connected at its lower end to the outside of the upper baffle and has a heating element to regulate the temperature of the upper baffle through heat conduction. The passage is selectively opened or closed according to the raising or lowering of the upper baffle.

12. A plasma density control method, characterized in that, include: The contour confirmation step confirms the geometric contour of the baffle unit that corresponds to the required plasma density distribution. The parameter adjustment value setting step involves setting adjustment values ​​for the plasma adjustment medium parameters based on the geometric contour of the baffle unit. The parameter adjustment step involves adjusting one or more of the dimensions of the exhaust port of the upper baffle of the baffle unit and the height of the upper baffle, based on the adjustment value of the plasma adjustment medium parameter; and The plasma density adjustment step adjusts the plasma density distribution in the process space of the substrate processing apparatus by adjusting the parameters of the plasma adjustment medium.

13. The plasma density control method according to claim 12, characterized in that, The parameter adjustment step involves lowering the upper baffle to adjust its height, using the edge ring of the substrate support unit as a reference.

14. The plasma density control method according to claim 13, characterized in that, The parameter adjustment step uses the edge ring of the substrate support unit as a reference to lower the upper baffle to a selected descent height within the range of less than 40mm.

15. The plasma density control method according to claim 12, characterized in that, The parameter adjustment step adjusts the size of the exhaust hole of the upper baffle by means of the exhaust hole adjustment component of the baffle unit.

16. The plasma density control method according to claim 15, characterized in that, The parameter adjustment step adjusts the size of the exhaust hole of the upper baffle to a diameter selected within a range of less than 10mm.

17. The plasma density control method according to claim 12, characterized in that, The parameter adjustment step involves adjusting the height of the upper baffle while keeping the size of the exhaust hole of the upper baffle fixed.

18. The plasma density control method according to claim 12, characterized in that, The plasma density control method further includes: In the exhaust step, gas is discharged through the upper baffle and the lower baffle located below the upper baffle.

19. The plasma density control method according to claim 12, characterized in that, The adjustment value of the plasma adjustment medium parameter is pre-stored based on the geometric contour of the baffle unit corresponding to the required plasma density distribution, and the adjustment value of the plasma adjustment medium parameter is pre-stored based on the geometric contour of the baffle unit.

20. A substrate processing apparatus, characterized in that, include: The cavity provides space for the process; A substrate support unit is disposed in the process space and on which a substrate is placed and supported, and includes an edge ring mounted on the outer contour of the substrate; A baffle unit is disposed around the substrate support unit to discharge gas from the process space, and includes an upper baffle, a lower baffle, an exhaust port adjustment component, an upper baffle lifting part, and an exhaust component. The upper baffle is an annular plate with exhaust ports that can be raised and lowered, and the lower baffle is an annular plate without exhaust ports located below the upper baffle. The exhaust port adjustment component adjusts the size of the exhaust ports of the upper baffle, the upper baffle lifting part raises and lowers the upper baffle, and the exhaust component discharges gas through the upper baffle and the lower baffle. as well as The control unit adjusts the plasma density distribution by using the size of the exhaust hole of the upper baffle and the height resulting from the descent of the upper baffle relative to the edge ring as plasma adjustment medium parameters, based on the required plasma density distribution. The size of the exhaust hole and the height of the upper baffle are controlled such that the diameter of the exhaust hole of the upper baffle is selected within a range of 10 mm or less, and the height of the upper baffle is selected within a descent range of 40 mm relative to the edge ring of the substrate support unit.

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