Substrate placing table, substrate processing apparatus, and substrate processing method

Abstract

To provide a substrate mounting table, a substrate processing device, and a substrate processing method that suppress non-uniform substrate processing at positions corresponding to lift pins.SOLUTION: A substrate mounting table having a mounting surface on which a substrate is placed includes a base material located below the mounting surface and composed of a conductor, an elevating pin that is made of a conductor and that moves up and down with respect to the mounting surface, and a pin hole, which has an opening in the placement surface and is formed inside the base material, into which the elevating pin protrudes and sinks, and the elevating pin includes an upper portion capable of contacting the substrate, and a lower portion connected to the lower side of the upper portion, and the upper portion has a hollow portion.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a substrate mounting table, a substrate processing apparatus, and a substrate processing method. [Background technology]

[0002] Patent Document 1 discloses a substrate mounting table that, when performing plasma processing on a substrate, suppresses non-uniformity in processing at positions of the mounting table body that correspond to insertion holes for lift pins. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-273685 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a substrate mounting table, a substrate processing apparatus, and a substrate processing method that suppress uneven substrate processing at positions corresponding to lift pins. [Means for solving the problem]

[0005] According to one aspect of the present disclosure, there is provided a substrate mounting table having a mounting surface on which a substrate is placed, the substrate comprising: a base material located below the mounting surface and made of a conductor; lifting pins made of a conductor and rising and falling relative to the mounting surface; and pin holes having openings on the mounting surface and formed inside the base material, through which the lifting pins protrude and sink, the lifting pins comprising an upper portion capable of contacting the substrate and a lower portion connected to the underside of the upper portion, and the substrate mounting table having a hollow portion in the upper portion. [Effects of the Invention]

[0006] The present disclosure provides a substrate mounting table, a substrate processing apparatus, and a substrate processing method that suppress uneven substrate processing at positions corresponding to lift pins. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a cross-sectional view showing a substrate processing apparatus including a substrate mounting table according to this embodiment. [Figure 2] FIG. 2 is an enlarged cross-sectional view of the substrate mounting table according to this embodiment. [Figure 3] FIG. 3 is an enlarged cross-sectional view of the substrate mounting table according to this embodiment. [Figure 4] FIG. 4 is a partial side view of the lift pins provided on the substrate mounting table according to this embodiment. [Figure 5] FIG. 5 is a diagram illustrating the characteristics of the heat transfer coefficient with respect to pressure. [Figure 6] FIG. 6 is a diagram illustrating the heat transfer coefficient of the substrate mounting table according to this embodiment. [Figure 7] FIG. 7 is a flowchart illustrating a substrate processing method using a substrate processing apparatus including a substrate mounting table according to this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In this specification and the drawings, substantially identical components are designated by the same reference numerals, and redundant description will be omitted.

[0009] In the directions of parallel, right-angle, orthogonal, horizontal, vertical, up / down, left / right, etc., deviations are permitted to the extent that they do not impair the effects of the embodiments. The shape of the corners is not limited to right angles and may be rounded like an arch. Parallel, right-angle, orthogonal, horizontal, and vertical may include approximately parallel, approximately right-angle, approximately orthogonal, approximately horizontal, and approximately vertical.

[0010] 1 is a cross-sectional view showing a substrate processing apparatus 1 including a substrate mounting table 20 according to this embodiment. The substrate processing apparatus 1 is, for example, a plasma etching apparatus. The substrate processing apparatus 1 is, for example, a capacitively coupled parallel plate plasma etching apparatus.

[0011] The substrate processing apparatus 1 is an apparatus that performs etching processing on, for example, a glass substrate G for a flat panel display (FPD). Examples of flat panel displays include a liquid crystal display, a light emitting diode display, an electroluminescence display, a fluorescent display tube, and a plasma display.

[0012] The substrate processing apparatus 1 includes a processing chamber 10, a substrate mounting table 20, a power supply unit 30, a gas supply unit 40, and an exhaust unit 50.

[0013] [Processing vessel 10] The processing vessel 10 is a so-called processing chamber. The processing vessel 10 is made of, for example, aluminum or an aluminum alloy whose surface has been anodized (anodized). The processing vessel 10 has a rectangular cylindrical shape.

[0014] The processing vessel 10 includes a shower head 11 at its top. The shower head 11 functions as an upper electrode, facing parallel to the substrate mounting table 20. The shower head 11 supplies gas to a processing space 10S of the processing vessel 10.

[0015] The shower head 11 is provided above the substrate mounting table 20. The shower head 11 is supported on the upper part of the processing chamber 10. The shower head 11 is grounded. The shower head 11 and the substrate mounting table 20 form a pair of parallel plate electrodes.

[0016] The shower head 11 has an internal space 11a therein and a plurality of outlet holes 11b through which a processing gas is discharged onto a surface facing the substrate mounting table 20.

[0017] A gas inlet 11c is provided on the top surface of the shower head 11. A processing gas supply pipe 40p is connected to the gas inlet 11c. A gas supply unit 40 is connected to the processing gas supply pipe 40p.

[0018] The processing vessel 10 has a bottom wall 10a provided with a spacer member 12 for placing the substrate mounting table 20 thereon. The spacer member 12 is made of an insulating material. The spacer member 12 is provided to correspond to the outer shape of the substrate mounting table 20. The substrate mounting table 20 is placed on the spacer member 12. The substrate mounting table 20 is composed of a main body 21 and an insulating member 22.

[0019] The gap between the spacer member 12 and the bottom wall 10a, and the gap between the spacer member 12 and the main body 21 and the insulating member 22 are airtightly sealed. Therefore, a space 10A of atmospheric air is formed between the main body 21 and the bottom wall 10a of the substrate mounting table 20. The space 10A provides insulation from the atmosphere.

[0020] The processing vessel 10 includes a plurality of insulating members 13. The insulating members 13 are embedded in the bottom wall 10a of the processing vessel 10. Bolts 14 are inserted into through holes provided vertically in the centers of the insulating members 13. The bolts 14 fasten the main body 21 of the substrate mounting table 20 to the bottom wall 10a. By fastening the main body 21 to the bottom wall 10a using the plurality of bolts 14, it is possible to prevent the substrate mounting table 20 from bending due to the pressure difference between the processing space 10S in a vacuum atmosphere and the space 10A in an air atmosphere, even when the inside of the processing vessel 10 is maintained at a vacuum.

[0021] The processing vessel 10 includes an exhaust pipe 15 connected to the bottom wall 10a. The exhaust pipe 15 is connected to an exhaust unit 50. The exhaust unit 50 exhausts the processing space 10S of the processing vessel 10. The exhaust unit 50 evacuates the processing space 10S of the processing vessel 10 to a predetermined reduced pressure.

[0022] The processing vessel 10 is provided on a side wall with a substrate loading / unloading port 16 and a gate valve 17 for opening and closing the substrate loading / unloading port 16. With the gate valve 17 open, the substrate processing apparatus 1 transfers a glass substrate G between the processing vessel 1 and an adjacent load lock chamber (not shown).

[0023] [Board mounting table 20] The substrate processing apparatus 1 includes a substrate mounting table 20 on the bottom of a processing chamber 10, on which a glass substrate G, which is a substrate to be processed, is mounted. The substrate mounting table 20 mounts the glass substrate G on a mounting surface 20S. That is, the substrate mounting table 20 has a mounting surface 20S. The substrate mounting table 20 is disposed inside the processing chamber 10.

[0024] The substrate mounting table 20 includes a main body 21, an insulating member 22, and a plurality of substrate lifting units 23. FIGS. 2 and 3 are enlarged cross-sectional views of the substrate mounting table 20 according to this embodiment. Specifically, FIGS. 2 and 3 are enlarged cross-sectional views of the substrate lifting units 23 of the substrate mounting table 20. FIG. 2 shows a state in which a glass substrate G is mounted on the substrate mounting table 20 and the lifting pins 23a are retracted inside the substrate mounting table 20. The state shown in FIG. 2 is referred to as the retracted state. FIG. 3 shows a state in which the glass substrate G is lifted from the substrate mounting table 20 by the lifting pins 23a. The state shown in FIG. 3 is referred to as the supported state.

[0025] (Main body 21) When high frequency power is supplied from the power supply unit 30, the main body unit 21 acts as a lower electrode.

[0026] The main body 21 includes a base material 21a, a dielectric layer 21b, a plurality of protrusions 21c, and a bank portion 21d. The bank portion 21d is formed in a frame shape around the periphery of the upper surface of the main body 21, protruding upward from the dielectric layer 21b. The main body 21 includes pin holes 21h through which elevating pins 23a of the substrate elevating unit 23 protrude. The pin holes 21h penetrate the base material 21a and the dielectric layer 21b. The pin holes 21h open to the mounting surface 20S. The mounting surface 20S also has a plurality of cooling gas holes (not shown) for supplying a cooling gas (back-cooling gas) such as helium. The cooling gas such as helium is supplied between the mounting surface 20S and the lower surface (rear surface) of the glass substrate G and exchanges heat with the glass substrate G to adjust the temperature of the glass substrate G.

[0027] The substrate 21a is made of a conductive material, i.e., a conductor. The substrate 21a is made of, for example, a metal. Specifically, the substrate 21a is made of, for example, aluminum, an aluminum alloy, a stainless steel alloy, or a combination of an aluminum alloy and a stainless steel alloy. The substrate 21a is located below the placement surface 20S. A substrate lifting unit 23 is attached to the substrate 21a.

[0028] The main body 21 includes a dielectric layer 21b on top of a base material 21a. The dielectric layer 21b is made of a dielectric material such as ceramics. An electrode 21b1 for electrostatic attraction is embedded inside the dielectric layer 21b. The electrode 21b1 is an electrostatic attraction electrode. A voltage is applied to the electrode 21b1 from an external power supply (not shown). When a voltage is applied to the electrode 21b1, the glass substrate G is attracted by Coulomb force. The electrode 21b1 is made of, for example, tungsten.

[0029] The base material 21a has a flow path (not shown) inside. A heat medium set to a predetermined temperature flows through the flow path of the base material 21a, thereby adjusting the temperature of the base material 21a to a predetermined desired temperature.

[0030] The main body 21 has a plurality of protrusions 21c and banks 21d on the upper part of the dielectric layer 21b. The protrusions 21c and banks 21d are formed of, for example, a dielectric material. The protrusions 21c are formed in a protruding shape on the upper part of the dielectric layer 21b, and the banks 21d are provided on the peripheral part of the upper part of the dielectric layer 21b. The upper surface of the banks 21d and the upper surface of the protrusions 21c are higher than or at the same height as the upper surface of the protrusions 21c. When the glass substrate G is placed on the substrate mounting table 20, the glass substrate G is in contact with the upper surface of the banks 21d, or with the upper surfaces of the banks 21d and the protrusions 21c. Note that the main body 21 does not necessarily have to have a plurality of protrusions 21c, and the area inside the banks 21d may be flat. Furthermore, when the area inside the bank portion 21d is to be a flat surface, it may be roughened.

[0031] (insulating member 22) The substrate mounting table 20 includes an insulating member 22 provided to surround the periphery of the base material 21a. The upper surface of the insulating member 22 is slightly lower than the upper surface of the bank portion 21d of the main body portion 21, and does not come into contact with the glass substrate G, forming a gap (for example, about 0.1 to 0.3 mm). The insulating member 22 may be divided into multiple members, such as an upper member and a lower member.

[0032] (Substrate lifting unit 23) The substrate lifting unit 23 supports the glass substrate G above and spaced apart from the substrate mounting table 20 when loading and unloading the glass substrate G onto and from the substrate mounting table 20. The glass substrate G supported above and spaced apart from the substrate mounting table 20 is carried in and out by a transport device.

[0033] The substrate lifting unit 23 is inserted into the processing vessel 10 from the outside of the bottom wall 10a. The substrate lifting unit 23 includes lifting pins 23a, a holder 23b, an O-ring 23d, a connection unit 23e, and a lifting unit 23f.

[0034] (Lifting pin 23a) The lifting pins 23a support the glass substrate G. The lifting pins 23a also raise and lower the glass substrate G. The lifting pins 23a protrude and sink into pin holes 21h formed in the main body 21. The lifting pins 23a are made of a conductive material.

[0035] 4 is a partial side view of a lift pin 23a provided on the substrate mounting table 20 according to this embodiment. The lift pin 23a has an upper part 23a1 and a lower part 23a2. The lower part 23a2 is connected to the underside of the upper part 23a1. The lift pin 23a has a shape that is rotationally symmetrical with respect to the central axis AX.

[0036] The upper portion 23a1 of the lift pin 23a has a central axis AX and a cylindrical shape with a diameter D2. The diameter D2 of the upper portion 23a1 is smaller than the diameter D1 of the pin hole 21h. Therefore, even when the lift pin 23a moves up and down, the lift pin 23a does not come into contact with the inner surface of the pin hole 21h. This prevents the lift pin 23a from coming into contact with the inner surface of the pin hole 21h, thereby preventing the generation of particles and the like.

[0037] In the substrate mounting table 20 according to this embodiment, the difference between the diameter D1 of the pin hole 21h and the diameter D2 of the upper portion 23a1 of the lift pin 23a is 0.1 millimeters or less. By making the difference between the diameter D1 and the diameter D2 0.1 millimeters or less, heat transfer between the base material 21a and the lift pin 23a is promoted. A cooling gas (back-cooling gas) such as helium supplied between the mounting surface 20S and the rear surface of the glass substrate G is filled between the base material 21a and the lift pin 23a via the opening of the pin hole 21h. By promoting heat transfer between the base material 21a and the lift pin 23a through the cooling gas, the temperature difference between the base material 21a and the lift pin 23a is reduced. By reducing the temperature difference between the base material 21a and the lift pin 23a, fluctuations in the temperature distribution around the lift pin 23a on the base material 21a can be suppressed.

[0038] Fig. 5 is a diagram illustrating the characteristics of heat transfer coefficient with respect to pressure. Fig. 5 shows the heat transfer coefficient when a gas such as helium is interposed between two members as a heat transfer medium. The horizontal axis of Fig. 5 represents pressure. The vertical axis of Fig. 5 represents the heat transfer coefficient.

[0039] The pressure P0 in FIG. 5 indicates the pressure when the mean free path of the gas is equal to the distance (representative distance) between the two members.

[0040] The heat transfer of gas changes at the pressure where the characteristic distance becomes the mean free path. In other words, the heat transfer of gas does not simply depend on the pressure, but also on whether the space in which the gas exists is a viscous flow region or a molecular flow region.

[0041] As shown in Figure 5, when the pressure is lower than pressure P0, in other words, when the representative distance is shorter than the free mean path of the gas, the region is molecular flow. In the molecular flow region, the heat transfer coefficient increases approximately in proportion to the pressure. In the molecular flow region, even if the distance is changed, the change in the heat transfer coefficient is small. Therefore, in the molecular flow region, the heat transfer coefficient depends on the pressure, and as the pressure increases, the heat transfer coefficient increases. On the other hand, if the pressure is constant, even if the distance is changed, the heat transfer coefficient does not change significantly.

[0042] When the pressure is higher than pressure P0, in other words, when the characteristic length is longer than the free mean path of the gas, the region is a viscous flow region. In the viscous flow region, the heat transfer coefficient is constant (heat transfer coefficient α0) regardless of pressure. In the viscous flow region, the heat transfer coefficient does not change even if the pressure is increased. Therefore, in the viscous flow region, the heat transfer coefficient depends on the characteristic distance, i.e., the distance between two parts, and as the characteristic distance increases, the heat transfer coefficient decreases. On the other hand, in the viscous flow region, if the characteristic distance is constant, the heat transfer coefficient does not change even if the pressure is changed.

[0043] Fig. 6 is a diagram illustrating the heat transfer coefficient between the base material 21a and the lift pins 23a in the substrate mounting table 20 according to this embodiment. Fig. 6 shows the heat transfer coefficient between the base material 21a and the lift pins 23a when helium is used as the heat medium.

[0044] The horizontal axis of Fig. 6 represents the distance (unit: millimeters) between the substrate 21a and the lift pins 23a, and the vertical axis of Fig. 6 represents the heat transfer coefficient (unit: watts per square meter per Kelvin) between the substrate 21a and the lift pins 23a.

[0045] 6, line Lp1 shows the results when the helium pressure is 66.7 Pascals (0.5 Torr), line Lp2 shows the results when the helium pressure is 200 Pascals (1.5 Torr), and line Lp3 shows the results when the helium pressure is 400 Pascals (3 Torr). These pressure ranges are examples of the range of conditions for using the substrate mounting table 20.

[0046] As shown in FIG. 6, by setting the gap between the substrate 21a and the lift pins 23a to 0.05 mm or less, the thermal conductivity remains high and constant within the range of conditions under which the substrate mounting table 20 is used. Therefore, by setting the gap to 0.05 mm or less, heat can be transferred between the substrate 21a and the lift pins 23a at a high heat transfer rate. By transferring heat between the substrate 21a and the lift pins 23a at a high heat transfer rate, the temperature difference between the substrate 21a and the lift pins 23a can be reduced. By reducing the temperature difference between the substrate 21a and the lift pins 23a, the temperature between the substrate 21a and the lift pins 23a can be made uniform.

[0047] When the outer periphery of upper portion 23a1 is positioned evenly relative to the inner periphery of pin hole 21h, the distance between base material 21a and lift pin 23a is half the difference between diameter D1 of pin hole 21h and diameter D2 of upper portion 23a1. Therefore, in order to keep the distance between base material 21a and lift pin 23a at 0.05 mm or less, it is desirable to set the difference between diameter D1 of pin hole 21h and diameter D2 of upper portion 23a1 of lift pin 23a at 0.1 mm or less.

[0048] When the lifting pins 23a are raised, the upper surfaces 23aA of the upper portions 23a1 support the glass substrate G. In other words, the upper surfaces 23aA of the upper portions 23a1 serve as a support surface that supports the glass substrate G. The lifting pins 23a are capable of coming into contact with the glass substrate G at the upper surfaces 23aA of the upper portions 23a1.

[0049] The side surface 23aB of the lift pin 23a forms a sealing surface that comes into contact with the O-ring 23d. When the lift pin 23a is in the retracted state (see FIG. 2), the side surface 23aB of the upper portion 23a1 comes into contact with the O-ring 23d. The contact between the side surface 23aB of the lift pin 23a and the O-ring 23d maintains airtightness between the lift pin 23a and the O-ring 23d. In other words, the contact between the side surface 23aB of the lift pin 23a and the O-ring 23d ensures airtightness between the lift pin 23a and the holder 23b.

[0050] For example, a cooling gas (back-cooling gas) such as helium may flow between the lower surface (rear surface) of the glass substrate G and the mounting surface 20S. By ensuring airtightness between the lifting pins 23a and the holder 23b, leakage of the cooling gas below the pin holes 21h can be suppressed. Suppressing leakage of the cooling gas can improve temperature stability.

[0051] The upper portion 23a1 of the lift pin 23a has a cavity 23as inside the upper portion. The cavity 23as of the lift pin 23a can shield heat transferred from the lower side of the substrate lifting unit 23 via the lower portion 23a2. When viewed from the top-bottom direction, the cross-sectional area of ​​the cavity 23as reduces the portion through which heat is transferred from the lower side of the substrate lifting unit 23, thereby reducing the amount of heat transferred from the lower side of the substrate lifting unit 23. Meanwhile, the provision of the cavity 23as reduces the heat capacity of the upper portion 23a1, thereby improving the thermal responsiveness of the upper surface 23aA of the upper portion 23a1 to the substrate 21a. This reduces the temperature difference between the upper surface 23aA of the upper portion 23a1 and the substrate 21a. Therefore, the provision of the cavity 23as can uniform the temperature between the substrate 21a and the lift pin 23a.

[0052] The thickness of the side wall of the upper portion 23a1 where the cavity 23as is located is preferably set to a thickness that provides a heat capacity equal to or greater than that of the glass substrate G, taking into consideration heat input from the glass substrate G.

[0053] The lift pin 23a having the hollow portion 23as may be made by, for example, configuring the lift pin 23a with a plurality of parts and joining parts having a concave shape for forming the hollow portion 23as by adhesive, welding, etc. Furthermore, it is desirable that the shape of the hollow portion 23as has a shape that is rotationally symmetrical with respect to the central axis AX.

[0054] 2, 3, and 4, the shape of the hollow portion 23as is not limited to a cylindrical shape, and may be determined appropriately in consideration of heat capacity, heat conduction, etc. For example, the shape of the hollow portion 23as may be a triangular pyramid or a truncated cone, or a combined shape in which the upper side of the hollow portion 23as is a triangular pyramid or a truncated cone and the lower side is cylindrical.

[0055] The lower portion 23a2 of the lift pin 23a has a central axis AX and is cylindrical with a diameter D3, which is smaller than the inner diameter of the O-ring 23d.

[0056] (holder 23b) Holder 23b holds lift pins 23a so that they can be raised and lowered. Holder 23b has a shape that is rotationally symmetrical with respect to center axis AX. Holder 23b has a cylindrical shape with through holes 23bh therein. Lift pins 23a are provided to pass through through holes 23bh.

[0057] The holder 23b is fitted into a recess 21ah provided on the underside of the base material 21a. The holder 23b is made of an insulating material. Because the holder 23b is made of an insulating material, the base material 21a and the lift pins 23a are insulated from each other at the holder 23b. The lift pins 23a are electrically connected to the base material 21a via the connection parts 23e.

[0058] The holder 23b has a ring groove 23bg on the inner surface of the through hole 23bh, which holds the O-ring 23d. The O-ring 23d is provided in the ring groove 23bg.

[0059] (O-ring 23d) O-ring 23d ensures airtightness between lift pin 23a and holder 23b. O-ring 23d is provided in ring groove 23bg in holder 23b. O-ring 23d is interposed between upper portion 23a1 of lift pin 23a and ring groove 23bg. By interposing O-ring 23d between upper portion 23a1 of lift pin 23a and ring groove 23bg, O-ring 23d ensures airtightness between lift pin 23a and holder 23b.

[0060] (Connection part 23e) The connecting portion 23e connects the main body 21 and the lifting portion 23f. The connecting portion 23e is made of, for example, a bellows. The connecting portion 23e is made of a conductive material.

[0061] (Lifting section 23f) The lifting unit 23f moves the lifting pins 23a in the vertical direction. The lifting unit 23f is configured by, for example, a motor. The lifting unit 23f drives the motor to move the lifting pins 23a in the vertical direction.

[0062] The lifting / lowering unit 23f can adjust the distance between the upper surfaces 23aA of the upper ends of the lifting pins 23a and the mounting surface 20S. That is, the lifting / lowering unit 23f can adjust the distance between the upper surfaces 23aA of the lifting pins 23a and the mounting surface 20S. By adjusting the distance between the upper surfaces 23aA of the lifting pins 23a and the mounting surface 20S, the electric field distribution can be adjusted. For example, the upper portions 23a1 of the lifting pins 23a are adjusted to be positioned near the glass substrate G. Specifically, the distance between the upper portions 23a1 of the lifting pins 23a and the mounting surface 20S on which the glass substrate G is placed is adjusted to be 0.02 mm or more and 0.2 mm or less, for example, 0.06 mm.

[0063] [Power supply section 30] The power supply unit 30 supplies high-frequency power to the base material 21a of the substrate mounting table 20. The power supply unit 30 is connected to the base material 21a via a power supply line 30w. The power supply unit 30 includes high-frequency power sources 31a and 31b, and matching boxes 32a and 32b. The power supply line 30w branches into a power supply line 30wa and a power supply line 30wb. The branched power supply line 30wa is connected to the matching box 32a. The branched power supply line 30wb is connected to the matching box 32b.

[0064] The high-frequency power supply 31a is a high-frequency power supply for generating plasma. The frequency of the high-frequency power generated by the high-frequency power supply 31a is, for example, 13.56 MHz. The high-frequency power supply 31a outputs the high-frequency power to the matching box 32a. The matching box 32a matches impedance and outputs the high-frequency power for generating plasma to the substrate 21a via the power feeder 30wa and the power feeder 30w.

[0065] The high-frequency power supply 31b is a high-frequency power supply for generating a bias. The frequency of the high-frequency power generated by the high-frequency power supply 31b is, for example, 3.2 MHz. The high-frequency power supply 31b outputs the high-frequency power to the matching box 32b. The matching box 32b matches impedance and outputs the high-frequency power for generating the bias to the substrate 21a via the power feeder 30wb and the power feeder 30w.

[0066] [Gas supply unit 40] The gas supply unit 40 supplies a processing gas for processing the glass substrate G to the processing chamber 10. The gas supply unit 40 includes a processing gas supply source 41, a mass flow controller 42, and a valve 43.

[0067] The processing gas supply source 41 supplies a gas for processing the glass substrate G. The processing gas supply source 41 supplies a gas typically used in this field, such as a halogen-based gas, oxygen gas, or argon gas, as a processing gas for etching a metal film, a silicon oxide film, a silicon nitride film, or the like formed on the glass substrate G.

[0068] The mass flow controller 42 adjusts the flow rate of the processing gas supplied from the processing gas supply source 41. The processing gas whose flow rate is adjusted by the mass flow controller 42 passes through a valve 43 and is supplied to the shower head 11 via a processing gas supply pipe 40p.

[0069] [Exhaust section 50] The exhaust unit 50 exhausts the processing space 10S of the processing chamber 10. The exhaust unit 50 includes a vacuum pump 51. The vacuum pump 51 is connected to the exhaust pipe 15. The vacuum pump 51 is, for example, a turbomolecular pump.

[0070] The power supply unit 30 and the gas supply unit 40 may be collectively referred to as a plasma generation unit.

[0071] <Substrate processing method> A substrate processing method using the substrate processing apparatus 1 including the substrate mounting table 20 according to this embodiment will be described. Fig. 7 is a flow chart illustrating the substrate processing method using the substrate processing apparatus 1 including the substrate mounting table 20 according to this embodiment. The steps of the substrate processing method according to this embodiment will be described in detail with reference to Fig. 7.

[0072] (Step S10) When processing starts, the glass substrate G is loaded into the processing chamber 10 of the substrate processing apparatus 1. Specifically, with the gate valve 17 open, the glass substrate G is transferred from the substrate loading / unloading port 16 into the processing chamber 10 by a transfer device.

[0073] (Step S20) Next, the lift pins 23a are raised to protrude from the placement surface 20S. Then, the carried-in glass substrate G is placed on the support surface of the protruding lift pins 23a. Then, the glass substrate G is supported by the lift pins 23a.

[0074] The transfer device that has loaded the glass substrate G leaves the processing chamber 10. Then, the gate valve 17 is closed.

[0075] (Step S30) Next, the lift pins 23a are lowered and stored in the pin holes 21h. When the lift pins 23a are lowered and stored in the pin holes 21h, the glass substrate G is placed on the protrusions 21c and the bank portions 21d. By placing the glass substrate G on the protrusions 21c and the bank portions 21d, the glass substrate G is placed on the placement surface.

[0076] (Step S40) Next, the position of the lift pins 23a is adjusted. When the glass substrate G is placed on the placement surface, the upper portions 23a1 of the lift pins 23a, which have hollow portions 23as, are adjusted to be located near the glass substrate G. By adjusting the upper portions 23a1 of the lift pins 23a to be located near the glass substrate G, the electric field can be adjusted to be uniform.

[0077] (Step S50) Next, plasma processing is performed on the glass substrate G. In other words, processing is performed on the glass substrate G using plasma. Specifically, the plasma processing is performed by supplying processing gas from the gas supply unit 40 and supplying power from the power supply unit 30. After the plasma processing is completed, the processing gas is exhausted by the exhaust unit 50.

[0078] (Step S60) When the plasma processing on the glass substrate G is completed, the lifting pins 23a are raised and protruded from the placement surface 20S, and the plasma-processed glass substrate G is then lifted up by the protruding lifting pins 23a.

[0079] (Step S70) Next, the glass substrate G is unloaded from the processing chamber 10 in the substrate processing apparatus 1. Specifically, with the gate valve 17 open, the transfer device is inserted into the processing chamber 10 through the substrate loading / unloading port 16. Then, the glass substrate G is placed on the transfer device and unloaded from the processing chamber 10.

[0080] The substrate mounting table 20 according to this embodiment can prevent the electric field from becoming non-uniform at the substrate mounting table 20, which acts as a lower electrode, during plasma processing. Furthermore, the substrate mounting table 20 according to this embodiment can ensure temperature responsiveness and prevent the temperature from becoming non-uniform. The substrate mounting table 20 according to this embodiment can prevent the electric field from becoming non-uniform or the temperature from becoming non-uniform, thereby preventing the substrate processing from becoming non-uniform at the positions corresponding to the lift pins.

[0081] The substrate mounting table 20 according to this embodiment functions as a lower electrode when performing plasma processing in the substrate processing apparatus 1. The substrate mounting table 20, which also serves as the lower electrode, is provided with lifting pins 23a that raise and lower a glass substrate G, which is an example of a substrate. In order to move the lifting pins 23a up and down, the base material 21a of the substrate mounting table 20 has pinholes 21h.

[0082] Since the base material 21a has the pinholes 21h, when the substrate mounting table 20 is used as a lower electrode, the electric field may become non-uniform at the pinholes 21h. Also, the thermal response of the lift pins 23a may decrease at the pinholes 21h, causing the temperature of the substrate to rise.

[0083] According to the substrate mounting table 20 of this embodiment, by narrowing the distance between the pin holes 21h and the lift pins 23a, the range of the electric field drop is reduced, and it is possible to prevent the electric field from becoming non-uniform at the pin holes 21h. Furthermore, according to the substrate mounting table 20 of this embodiment, the lift pins 23a have hollow portions 23as, which reduces the heat capacity and improves thermal responsiveness, and also blocks heat transfer from below, thereby preventing the temperature from becoming non-uniform at the pin holes 21h.

[0084] When plasma processing is performed by the substrate processing apparatus 1, the glass substrate G receives heat input from the plasma. The glass substrate G also exchanges heat with the substrate mounting table 20 via a cooling gas (back-cooling gas) such as helium. In the substrate processing apparatus 1, the glass substrate G directly above the lift pins 23a exchanges heat with the tips of the lift pins 23a via a cooling gas (back-cooling gas) such as helium.

[0085] Generally, the temperature of a process chamber such as the processing vessel 10 is adjusted to about 80° C. to 110° C. to prevent reaction by-products from adhering to the process chamber. Therefore, the lift pins 23a receive heat input from the lower side (lift unit 23f side) of the substrate lift unit 23. The side surfaces of the lift pins 23a are cooled by heat transfer from the substrate mounting table 20 via a cooling gas (back-cooling gas) such as helium.

[0086] From the above, in order to make the temperature directly above the lift pins 23a closer to the temperature of the base material 21a on the substrate mounting table 20, the following two points are necessary. (a) The heat input from the lifting portion 23f side of the lifting pin 23a is reduced. (b) The efficiency of heat exchange between the lifting pins 23a and the base 21a of the substrate mounting table 20 is increased.

[0087] Considering (a), the amount of heat E transferred through lift pin 23a is calculated from the heat conduction formula as shown in Equation 1. Here, A is the cross-sectional area of ​​lift pin 23a, B is the axial thickness of lift pin 23a, C is the heat transfer coefficient of the material forming lift pin 23a, and D is the temperature difference.

[0088] E = A / B × C × D (Formula 1)

[0089] To reduce the heat input from the lifting / lowering section 23f, i.e., the heat quantity E, it is necessary to reduce the cross-sectional area A or the heat transfer coefficient C. If the heat transfer coefficient C is reduced, the heat conduction in the horizontal direction (the direction parallel to the mounting surface 20S) at the tip of the lifting / lowering pin 23a decreases. To improve the temperature uniformity in the horizontal direction, it is necessary to increase the heat transfer coefficient C, for example, by using a metal material such as stainless steel.

[0090] Therefore, in the substrate mounting table 20 according to this embodiment, it is effective to reduce the cross-sectional area A, and the provision of the hollow portion 23as in the lift pin 23a reduces the cross-sectional area A. When forming the hollow portion 23as, it is desirable that the thickness of the side wall be set to have a heat capacity equal to or greater than that of the substrate, taking into account the heat input from the substrate.

[0091] 6, by setting the distance between the base 21a and the lift pins 23a to 0.05 mm or less, the efficiency of heat exchange between the lift pins 23a and the base 21a of the substrate mounting table 20 can be increased. In order to set the distance between the base 21a and the lift pins 23a to 0.05 mm or less, it is desirable to set the difference between the diameter D1 of the pinholes 21h and the diameter D2 of the upper portions 23a1 of the lift pins 23a to 0.1 mm or less.

[0092] In the above explanation, the case of processing a glass substrate G has been described, but the substrate to be processed is not limited to a glass substrate, and may be, for example, a semiconductor substrate formed from silicon, gallium, or an alloy thereof.

[0093] The substrate support table, substrate processing apparatus, and substrate processing method according to the presently disclosed embodiments are illustrative in all respects and should not be considered limiting. For example, although the above description has been given of a capacitively coupled parallel plate plasma etching apparatus as the substrate processing apparatus, other types of plasma apparatuses, such as an inductively coupled plasma apparatus, may also be used. Furthermore, the substrate processing is not limited to etching processing, and may be other substrate processing such as film formation processing or ashing processing. The above embodiments may be modified and improved in various ways without departing from the spirit and scope of the appended claims. The features described in the above embodiments may be configured differently and may be combined within a consistent range. [Explanation of symbols]

[0094] 1. Substrate processing equipment 10 Processing container 20 Board mounting table 20S Placement surface 21 Main body 21a Base material 21h pin hole 23 Substrate lifting unit 23a Lifting pin 23a1 upper part 23a2 bottom 23as Cavity 23b Holder 23bg ring groove 23bh through hole 23d O-ring 30 Power supply section 40 Gas supply unit AX center axis

Claims

1. A substrate mounting table having a mounting surface on which a substrate is placed, a substrate made of a conductor and located below the mounting surface; a lifting pin that is made of a conductor and moves up and down relative to the placement surface; pin holes that open to the mounting surface and are formed inside the base material, and through which the lift pins protrude and retract; Equipped with the lift pins each include an upper portion that can contact the substrate and a lower portion that is connected to a lower side of the upper portion; A cavity is formed inside the upper portion. Board mounting table.

2. The difference between the diameter of the upper portion and the diameter of the pin hole is 0.1 millimeters or less. The substrate mounting table according to claim 1 .

3. A substrate processing apparatus for processing a substrate inside a processing vessel, a substrate mounting table disposed inside the processing chamber and configured to mount the substrate thereon; a plasma generating unit that generates plasma for processing the substrate inside the processing chamber; Equipped with The substrate mounting table is a mounting surface on which the substrate is placed, a base material located below the mounting surface, made of a conductor, and connected to a high-frequency power source; a lifting pin that is made of a conductor and moves up and down relative to the placement surface; pin holes that open to the mounting surface and are formed inside the base material, and through which the lift pins protrude and retract; Equipped with the lift pins each include an upper portion that can contact the substrate and a lower portion that is connected to a lower side of the upper portion; A cavity is formed inside the upper portion. Substrate processing equipment.

4. The difference between the diameter of the upper portion and the diameter of the pin hole is 0.1 millimeters or less. The substrate processing apparatus according to claim 3 .

5. A substrate processing method for processing a substrate inside a processing container of a substrate processing apparatus, comprising: The substrate processing apparatus includes: a substrate mounting table disposed inside the processing chamber and configured to mount the substrate thereon; a plasma generating unit that generates plasma for processing the substrate inside the processing chamber; Equipped with The substrate mounting table is a mounting surface on which the substrate is placed, a base material located below the mounting surface, made of a conductor, and connected to a high-frequency power source; a lifting pin that is made of a conductor and moves up and down relative to the placement surface; pin holes that open to the mounting surface and are formed inside the base material, and through which the lift pins protrude and retract; Equipped with the lift pins each include an upper portion that can contact the substrate and a lower portion that is connected to a lower side of the upper portion; A hollow portion is provided in the upper portion, loading the substrate into the processing chamber; a step of raising and protruding the plurality of lift pins above the mounting surface to support the substrate; a step of lowering the lift pins and storing them in the pin holes, and placing the substrate on the placement surface; adjusting the upper portion having the cavity to be positioned adjacent to the substrate; treating the substrate with the plasma; having Substrate processing method.

Images