Substrate processing apparatus and substrate processing method

Abstract

To provide a technique to remove dirt from a holder.SOLUTION: A substrate processing apparatus includes a processor configured to process a substrate with a processing liquid. The processor has a holder configured to hold the substrate horizontally. The holder includes a first holder configured to come into contact with a center of a bottom surface of the substrate. The processor has a rotation driver configured to rotate the first holder around a vertical rotation axis. The substrate processing apparatus includes a charging part configured to charge a second substrate prepared separately from the substrate, and a controller configured to carry out a control to bring the second substrate charged by the charging part into contact with the first holder.SELECTED DRAWING: Figure 9

Description

[Technical field]

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

[0002] The substrate processing apparatus described in Patent Document 1 includes two suction pads, a liquid receiving cup, a spin chuck, a housing, a first cleaning unit, and a second cleaning unit. The two suction pads horizontally suction and hold the lower surface of the substrate. The liquid receiving cup is connected to the two suction pads. The spin chuck horizontally suction and holds the lower surface of the substrate received from the suction pads. The housing has an opening with an open top. A drain pipe for discharging the cleaning liquid and an exhaust pipe for exhausting the airflow are provided at the bottom of the housing. The first cleaning unit cleans the upper surface of the substrate. The second cleaning unit cleans the lower surface of the substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-43156 A Summary of the Invention [Problem to be solved by the invention]

[0004] One aspect of the present disclosure provides a technique for removing dirt from a holder. [Means for solving the problem]

[0005] A substrate processing apparatus according to one embodiment of the present disclosure includes a processing section for processing a substrate with a processing liquid. The processing section has a holding section for holding the substrate horizontally. The holding section includes a first holding section that contacts the center of the underside of the substrate. The processing section has a rotation drive section for rotating the first holding section about a vertical rotation axis. The substrate processing apparatus includes a charging section for charging a second substrate prepared separately from the substrate, and a control section for controlling the contact of the second substrate charged by the charging section with the first holding section. Effect of the Invention

[0006] According to one aspect of the present disclosure, dirt on the holding portion can be removed. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a plan view showing a substrate processing apparatus according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view showing an example of the processing apparatus, and is a plan view showing an example of step S104 in FIG. [Diagram 3] FIG. 3 is a cross-sectional view showing an example of step S104 in FIG. [Figure 4] FIG. 4 is a plan view showing an example of step S102 in FIG. [Diagram 5] FIG. 5 is a cross-sectional view showing an example of step S102 in FIG. [Figure 6] FIG. 6 is a cross-sectional view showing an example of the operation of the lift pin. [Figure 7] FIG. 7 is a cross-sectional view showing an example of the operation of the lift pins subsequent to FIG. [Figure 8] FIG. 8 is a flowchart showing an example of the operation of the processing device. [Figure 9] FIG. 9 is a flow chart showing an example of cleaning of a processing device. [Figure 10] FIG. 10 is a cross-sectional view showing an example of step S202 in FIG. [Figure 11] FIG. 11 is a diagram showing an example of the distribution of electrostatic forces obtained in step S202. [Figure 12] FIG. 12 is a cross-sectional view showing an example of step S203 in FIG. [Figure 13] FIG. 13 is a cross-sectional view showing an example of step S204 in FIG. [Figure 14] FIG. 14 is a cross-sectional view showing an example of step S206 in FIG. [Figure 15]FIG. 15 is a diagram showing an example of the distribution of electrostatic forces obtained in step S206. [Figure 16] FIG. 16 is a diagram showing an example of the distribution of electrostatic forces obtained in step S206 when the third substrate is used instead of the second substrate. [Figure 17] FIG. 17 is a diagram showing an example of the number of particles adhering to a substrate after the processing apparatus is cleaned with a second substrate or a third substrate. [Figure 18] FIG. 18 is a diagram illustrating an example of the third holding portion. [Figure 19] FIG. 19 is a plan view showing an example of the wall portion. [Figure 20] FIG. 20 is a cross-sectional view showing an example of a wall portion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In each drawing, the same or corresponding configurations are denoted by the same reference numerals, and the description may be omitted. In this specification, the X-axis direction, the Y-axis direction, and the Z-axis direction are perpendicular to each other. The X-axis direction and the Y-axis direction are horizontal directions, and the Z-axis direction is vertical.

[0009] A substrate processing apparatus 100 according to one embodiment will be described with reference to FIG. 1. The substrate processing apparatus 100 processes a substrate W. The substrate W includes a semiconductor wafer such as a silicon wafer. The substrate W may include a plurality of devices formed on the semiconductor wafer. The devices include, for example, electronic circuits. The substrate W may be a laminated substrate formed by stacking a plurality of semiconductor wafers. The laminated substrate is obtained by bonding a plurality of semiconductor wafers.

[0010] The substrate processing apparatus 100 includes a loading / unloading station 110, a processing station 120, and a control device 190. The loading / unloading station 110 includes a mounting table 111. Cassettes C1 to C2 are mounted on the mounting table 111. The cassette C1 accommodates a substrate W before processing. The cassette C2 accommodates a substrate W after processing. The number of cassettes C1 and C2 is not particularly limited. A cassette (not shown) may accommodate a substrate W that has become defective during processing.

[0011] The loading / unloading station 110 includes a first transfer region 112 and a first transfer device 113. The first transfer region 112 extends in the Y-axis direction and is adjacent to the mounting table 111 and the transition device 121. The first transfer device 113 transfers the substrate W between a plurality of devices adjacent to the first transfer region 112. The first transfer device 113 includes a transfer arm that holds the substrate W, and a drive unit that moves or rotates the transfer arm. The transfer arm is capable of moving in the horizontal direction (both in the X-axis direction and the Y-axis direction) and the vertical direction, and of rotating about the vertical axis. A plurality of transfer arms may be provided.

[0012] The processing station 120 includes a transition device 121, a second transport area 122, a second transport device 123, a processing device 124, and a storage device 125. The second transport device 123 is an example of a transport section. The processing device 124 is an example of a processing section. The storage device 125 is an example of a storage section. The arrangement and number of devices constituting the processing station 120 are not limited to those shown in FIG. 1.

[0013] The transition device 121 temporarily stores the substrate W. The transition device 121 is provided between the first transfer region 112 and the second transfer region 122, and relays the substrate W between the first transfer device 113 and the second transfer device 123.

[0014] The second transfer region 122 extends in the X-axis direction and is adjacent to the transition device 121, the processing device 124, and the storage device 125. The second transfer device 123 transfers the substrate W between multiple devices adjacent to the second transfer region 122. The second transfer device 123 has a transfer arm that holds the substrate W, and a drive unit that moves or rotates the transfer arm. The transfer arm is capable of moving in the horizontal direction (both in the X-axis direction and the Y-axis direction) and the vertical direction, and of rotating about the vertical axis. Multiple transfer arms may be provided.

[0015] The processing device 124 processes the substrate W with a processing liquid. The processing liquid includes, for example, a chemical liquid and a rinsing liquid. The chemical liquid is not particularly limited, but may be, for example, SC1 (a mixture of ammonia, hydrogen peroxide, and water). The chemical liquid may be a cleaning liquid for removing dirt from the substrate W, as well as an etching liquid or a stripping liquid. The rinsing liquid is, for example, DIW (deionized water). The chemical liquid and the rinsing liquid may be supplied to the substrate W in this order.

[0016] The storage device 125 stores the second substrate W2 to be used for cleaning the processing device 124. The second substrate W2 is transported from the storage device 125 to the processing device 124 by the second transport device 123 and used to clean the processing device 124. Thereafter, the second substrate W2 is returned from the processing device 124 to the storage device 125 by the second transport device 123. The used second substrate W2 is replaced with an unused second substrate W2 during maintenance of the substrate processing device 100. Details regarding the second substrate W2 will be described later.

[0017] The control device 190 is, for example, a computer, and includes an arithmetic unit 191 such as a CPU (Central Processing Unit), and a storage unit 192 such as a memory. The storage unit 192 stores programs for controlling various processes executed in the substrate processing apparatus 100. The control device 190 controls the operation of the substrate processing apparatus 100 by causing the arithmetic unit 191 to execute the programs stored in the storage unit 192. A unit control unit that controls the operation of each unit constituting the substrate processing apparatus 100 may be provided, and a system control unit that controls a plurality of unit control units may be provided. The unit control units and the system control unit may constitute the control device 190. The control device 190 is an example of a control unit.

[0018] Next, a description will be given of an example of the operation of the substrate processing apparatus 100. First, the first transfer device 113 takes out the substrate W from the cassette C1 and transfers it to the transition device 121. Next, the second transfer device 123 takes out the substrate W from the transition device 121 and transfers it to the processing device .

[0019] Next, the processing device 124 processes the substrate W with a processing liquid. Thereafter, the second transfer device 123 takes the substrate W out of the processing device 124 and transfers it to the transition device 121. Finally, the first transfer device 113 takes the substrate W out of the transition device 121 and stores it in the cassette C2.

[0020] 2 to 7, an example of the processing device 124 will be described. As mainly shown in Fig. 3, the processing device 124 includes, for example, a first holding unit 11, a second holding unit 12, a rotation drive unit 13, a cup 20, a movement drive unit 25 (see Fig. 2), a processing liquid supply unit 30, a processing tank 40, a drain pipe 45, an exhaust pipe 46, an exhaust pipe cover 47, a friction body 50, and a friction body movement unit 55.

[0021] The first holding unit 11 contacts the center of the lower surface of the substrate W and holds the substrate W horizontally. The first holding unit 11 contacts only a portion of the lower surface of the substrate W. In this embodiment, the first holding unit 11 vacuum-adsorbs the substrate W, but may electrostatically adsorb the substrate W. The first holding unit 11 is, for example, a spin chuck, and is rotationally driven by the rotation drive unit 13. The first holding unit 11 is rotated about a vertical rotation axis. The first holding unit 11 may be movable in the Z-axis direction.

[0022] A plurality of lift pins 14 are arranged around the first holding part 11. The plurality of lift pins 14 lowers or raises the substrate W relative to the first holding part 11 or the second holding part 12. The plurality of lift pins 14 are arranged at equal intervals in the circumferential direction of the first holding part 11. The plurality of lift pins 14 raise and lower around the first holding part 11 to transfer the substrate W between the first holding part 11 or the second holding part 12 and a transport arm (not shown).

[0023] In addition, a gas discharge ring 15 is disposed around the first holding unit 11. The gas discharge ring 15 surrounds the first holding unit 11 and forms a ring-shaped gas curtain toward the underside of the substrate W. The gas curtain restricts the processing liquid from entering from the outside to the inside, thereby protecting the first holding unit 11. The gas curtain also protects the multiple lift pins 14 disposed inside the gas curtain. The gas discharge ring 15 is an example of a gas discharge unit. The gas discharge unit does not have to be ring-shaped.

[0024] The second holding part 12 contacts the lower surface of the substrate W radially outward of the substrate W relative to the first holding part 11, and holds the substrate W horizontally. The second holding part 12 contacts only a portion of the lower surface of the substrate W. In this embodiment, the second holding part 12 vacuum-adsorbs the substrate W, but may electrostatically adsorb the substrate W. The second holding part 12 includes a pair of suction pads 12A, 12B spaced apart in the X-axis direction. The pair of suction pads 12A, 12B are arranged to sandwich the first holding part 11 in the X-axis direction. The second holding part 12 is connected to the cup 20, and is movable together with the cup 20 in the horizontal direction (Y-axis direction) and vertical direction.

[0025] The cup 20 is ring-shaped and open both vertically and surrounds the periphery of the substrate W held by the first holding part 11 or the second holding part 12. The cup 20 has a cylindrical vertical wall 21 and an upper wall 22 that protrudes radially inward from the upper end of the cylindrical vertical wall 21. The cup 20 receives the processing liquid supplied to the substrate W.

[0026] The movement drive unit 25 moves the second holding unit 12 in a horizontal direction (Y-axis direction) and a vertical direction (Z-axis direction) perpendicular to the rotation axis of the first holding unit 11. The movement drive unit 25 moves the second holding unit 12 together with the cup 20. The cup 20 is moved inside the treatment tank 40. When viewed from above, the side surface 42 of the treatment tank 40 surrounds the entire movement range of the cup 20.

[0027] The processing liquid supply unit 30 supplies a processing liquid to the substrate W surrounded by the cup 20. The processing liquid includes, for example, a chemical liquid and a rinsing liquid. The chemical liquid is not particularly limited, but may be, for example, SC1 (a mixture of ammonia, hydrogen peroxide, and water). The chemical liquid may be a cleaning liquid for removing dirt from the substrate W, as well as an etching liquid or a stripping liquid. The rinsing liquid is, for example, DIW (deionized water). The chemical liquid and the rinsing liquid may be supplied to the substrate W in this order.

[0028] The processing liquid supply unit 30 has lower nozzles 31, 32 (see Figures 2 and 4) that supply processing liquid to the lower surface of the substrate W. The lower nozzles 31, 32 are each connected to a processing liquid supply source via piping (not shown). A valve and a flow rate controller are provided in the piping. When the valve opens the flow path of the piping, the processing liquid is discharged from the lower nozzles 31, 32. The amount of the discharge is controlled by the flow rate controller. On the other hand, when the valve closes the flow path of the piping, the discharge of the processing liquid is stopped.

[0029] The processing liquid supply unit 30 has an upper nozzle 33 (see FIG. 3) that supplies the processing liquid to the upper surface of the substrate W. The upper nozzle 33 is connected to a processing liquid supply source via a pipe (not shown) like the lower nozzles 31 and 32. The upper nozzle 33 may be a two-fluid nozzle, and the processing liquid may be pulverized and atomized with a gas such as N2 gas before being sprayed.

[0030] The processing liquid supply unit 30 has a nozzle movement unit 34 that moves the upper nozzle 33 in horizontal and vertical directions. The nozzle movement unit 34 moves the upper nozzle 33 between a position where the processing liquid is supplied to the substrate W surrounded by the cup 20 (see FIG. 3) and a position where the discharge port of the upper nozzle 33 is accommodated in the nozzle bath 35 (see FIG. 5).

[0031] The nozzle bath 35 is also called a dummy dispense port. Just before supplying the processing liquid from the upper nozzle 33 to the substrate W, old processing liquid (e.g., processing liquid whose temperature has been reduced) accumulated in the upper nozzle 33 is discharged into the nozzle bath 35, so that new processing liquid (e.g., processing liquid whose temperature has been controlled to a desired temperature) can be supplied to the substrate W. A discharge pipe is provided on the bottom wall of the nozzle bath 35. The discharge pipe discharges the processing liquid accumulated inside the nozzle bath 35 into the processing tank 40. The discharge pipe is provided vertically. The processing liquid flows down inside the discharge pipe due to gravity. The lower end of the discharge pipe is located above the bottom surface 43 of the processing tank 40.

[0032] The processing tank 40 collects the processing liquid that drops from the cup 20. The processing tank 40 is, for example, in the shape of a box that is open upward. An inner wall surface 41 of the processing tank 40 has a side surface 42 and a bottom surface 43. The bottom surface 43 has an outlet 44 for discharging the processing liquid. A drain pipe 45 is provided in the outlet 44. The drain pipe 45 discharges the processing liquid from the inside of the processing tank 40 to the outside. In addition to the drain pipe 45, an exhaust pipe 46 is provided in the bottom surface 43 of the processing tank 40. The exhaust pipes 46 are provided, for example, on both sides in the X-axis direction based on the rotation drive unit 13 (see FIG. 20).

[0033] The exhaust pipe 46 exhausts gas from the inside of the treatment tank 40 to the outside. The exhaust pipe 46 protrudes upward from the bottom surface 43 of the treatment tank 40. The upper part of the exhaust pipe 46 is covered with an exhaust pipe cover 47. The exhaust pipe cover 47 prevents droplets of the treatment liquid from entering the exhaust pipe 46. The exhaust pipe cover 47 also protects the rotary drive unit 13 from droplets of the treatment liquid. The exhaust pipe cover 47 extends in both the positive X-axis direction and the negative X-axis direction with the rotary drive unit 13 as the reference.

[0034] The friction body 50 rubs the lower surface of the substrate W. The friction body 50 is a brush or a sponge. The friction body 50 is, for example, cylindrical, and the upper surface of the friction body 50 is disposed horizontally. The upper surface of the friction body 50 is smaller than the lower surface of the substrate W. The friction body 50 is formed of a resin such as PVA (polyvinyl alcohol).

[0035] The friction body 50 is rotated by a rotary motor 51. The rotary motor 51 is provided at one end of an arm 53. A friction body moving unit 55 is provided at the other end of the arm 53. The friction body moving unit 55 moves the friction body 50 via the arm 53 in the horizontal and vertical directions.

[0036] Next, an example of the operation of the processing device 124 will be described with reference to Fig. 8. As shown in Fig. 8, the processing device 124 performs steps S101 to S106. Steps S101 to S106 are performed under the control of the control unit 90.

[0037] Step S101 includes carrying the substrate W from the outside to the inside of the processing apparatus 124. First, the transport arm of the second transport device 123 transports the substrate W above the cup 20, and waits above the cup 20. At this time, when viewed from above, the center of the substrate W, the center of the first holding part 11, and the center of the cup 20 overlap with each other, as shown in FIG.

[0038] Then, the lift pins 14 are raised, and the lift pins 14 lift the substrate W from the transport arm of the second transport device 123 (see FIG. 6). Instead of raising the lift pins 14, the transport arm may be lowered. Then, when the transport arm leaves the processing device 124, the cup 20 is raised and the lift pins 14 are lowered, and the lift pins 14 deliver the substrate W to the second holding unit 12 (see FIG. 7). Then, the second holding unit 12 adsorbs the peripheral portion of the lower surface of the substrate W. Then, as shown in FIG. 4, the movement drive unit 25 moves the second holding unit 12 together with the cup 20 in the horizontal direction to a position where the center of the lower surface of the substrate W overlaps with the friction body 50 when viewed from above.

[0039] Step S102 includes cleaning the central portion of the underside of the substrate W while the peripheral portion of the underside of the substrate W is being sucked by the second holding unit 12 (see FIG. 5). The lower nozzles 31, 32 supply a processing liquid to the underside of the substrate W, and the frictional body moving unit 55 moves the frictional body 50 in the horizontal direction while pressing it against the central portion of the underside of the substrate W. In addition, the movement drive unit 25 moves the second holding unit 12 together with the cup 20 in the horizontal direction. The movement direction of the frictional body 50 intersects with the movement direction of the cup 20.

[0040] Step S103 includes transferring the substrate W from the second holding unit 12 to the first holding unit 11. First, as viewed from above, as shown in Fig. 2, the movement drive unit 25 moves the second holding unit 12 together with the cup 20 in the horizontal direction to a position where the center of the substrate W overlaps with the center of the first holding unit 11. Thereafter, the movement drive unit 25 lowers the cup 20, causing the second holding unit 12 to deliver the substrate W to the first holding unit 11. The second holding unit 12 releases suction from the peripheral portion of the lower surface of the substrate W, and the first holding unit 11 suctions the central portion of the lower surface of the substrate W.

[0041] Step S104 includes cleaning the peripheral portion of the lower surface of the substrate W while the first holding unit 11 is holding the central portion of the lower surface of the substrate W by suction (see FIG. 3). The lower nozzles 31, 32 supply the processing liquid to the lower surface of the substrate W, and the friction body moving unit 55 moves the friction body 50 in the horizontal direction while pressing it against the peripheral portion of the lower surface of the substrate W. In addition, the rotation drive unit 13 rotates the substrate W together with the first holding unit 11.

[0042] Incidentally, while the rotary drive unit 13 rotates the substrate W together with the first holding unit 11, the upper surface of the substrate W is cleaned. For example, the upper nozzle 33 supplies the processing liquid to the upper surface of the substrate W. The upper nozzle 33 may supply the processing liquid to the center of the upper surface of the substrate W, or may be moved in the radial direction of the substrate W to supply the processing liquid over the entire radial direction of the substrate W. A second friction body (not shown) may rub the upper surface of the substrate W. Furthermore, a third friction body (not shown) may rub the bevel of the substrate W.

[0043] Step S105 includes drying the substrate W. For example, the rotary drive unit 13 rotates the first holding unit 11 at high speed to shake off the processing liquid adhering to the substrate W.

[0044] Step S106 includes unloading the substrate W from inside the processing apparatus 124 to outside. First, the first holding unit 11 releases the suction of the substrate W, and the multiple lift pins 14 are raised, and the multiple lift pins 14 lift the substrate W from the first holding unit 11. Next, the transport arm of the second transport device 123 enters the processing apparatus 124 from outside to inside and waits above the cup 20. Next, the multiple lift pins 14 are lowered, and the multiple lift pins 14 transfer the substrate W to the transport arm. Note that instead of lowering the lift pins 14, the transport arm may be raised. Thereafter, the transport arm holds the substrate W and exits the processing apparatus 124.

[0045] However, when the first holding part 11 holds the substrate W, dirt on the substrate W may be transferred to the first holding part 11, causing the first holding part 11 to become dirty. If the first holding part 11 then holds another substrate W, the other substrate W will become dirty. Thus, in the past, in order to remove dirt from the first holding part 11, an operator would periodically wipe off the dirt from the first holding part 11 with a fiber wipe such as a rag, or prepare a large number of clean substrates W and bring the large number of substrates W into contact with the first holding part 11 in turn.

[0046] In this embodiment, which will be described in detail later, a second substrate W2 is prepared separately from the substrate W, the second substrate W2 is charged, and then the second substrate W2 is brought into contact with the first holding unit 11. At this time, it is sufficient that the particles attached to the first holding unit 11 and the second substrate W2 have opposite polarities. The particles can be attached to the second substrate W2 by static electricity, and can be taken out of the first holding unit 11 together with the second substrate W2. This allows the first holding unit 11 to be efficiently cleaned.

[0047] As described below, the contents of the present disclosure can also be applied to cleaning the lift pins 14. Specifically, the second substrate W2 is charged, and then the second substrate W2 and the lift pins 14 are brought into contact with each other. At this time, it is sufficient that the particles attached to the lift pins 14 and the second substrate W2 have opposite polarities. The particles can be attached to the second substrate W2 by static electricity, and can be removed from the lift pins 14 together with the second substrate W2. This allows the lift pins 14 to be efficiently cleaned.

[0048] Next, an example of cleaning of the processing device 124 will be described with reference to Fig. 9 to Fig. 17. As shown in Fig. 9, the processing device 124 performs steps S201 to S206. Steps S201 to S206 are performed periodically under the control of the control unit 90. In steps S201 to S206, a prepared second substrate W2 is used instead of the substrate W.

[0049] 10, the second substrate W2 has, for example, a support substrate W2a and an oxide film W2b. In this embodiment, the support substrate W2a is a silicon wafer, but is not particularly limited thereto, and may be, for example, a compound semiconductor wafer or a glass substrate. In this embodiment, the oxide film W2b is a silicon oxide film, but is not particularly limited thereto, and may contain, for example, at least one of nitrogen and carbon in addition to oxygen.

[0050] The oxide film W2b can be charged to a positive polarity by rubbing with the friction body 50. On the other hand, it is known that particles are charged to a negative polarity in the presence of an alkaline aqueous solution. That is, the oxide film W2b can be charged to a polarity opposite to that of the particles. The method for forming the oxide film W2b is a thermal oxidation method in this embodiment, but may also be a chemical vapor deposition (CVD) method, an atomic layer deposition (ALD) method, or the like.

[0051] The second substrate W2 preferably has an oxide film W2b at least on its lower surface. This is because the processing device 124 is likely to accumulate particles below the second substrate W2. If the second substrate W2 has an oxide film W2b on its lower surface, particles present below the second substrate W2 can be adsorbed to the second substrate W2. Note that the second substrate W2 of this embodiment has the oxide film W2b on its entire surface.

[0052] Step S201 includes carrying the second substrate W2 from the outside to the inside of the processing device 124. First, the transport arm of the second transport device 123 transports the second substrate W2 above the cup 20, and waits above the cup 20. At this time, as viewed from above, the center of the second substrate W2, the center of the first holding part 11, and the center of the cup 20 overlap with each other, as shown in FIG.

[0053] Then, the lift pins 14 are raised, and the lift pins 14 lift the second substrate W2 from the transport arm of the second transport device 123 (see FIG. 6). Instead of raising the lift pins 14, the transport arm may be lowered. Then, when the transport arm leaves the processing device 124, the cup 20 is raised and the lift pins 14 are lowered, and the lift pins 14 deliver the second substrate W2 to the second holding unit 12 (see FIG. 7). Then, the second holding unit 12 adsorbs the periphery of the lower surface of the second substrate W2. Then, as shown in FIG. 4, the movement drive unit 25 moves the second holding unit 12 together with the cup 20 in the horizontal direction to a position where the center of the lower surface of the second substrate W2 overlaps with the friction body 50 when viewed from above.

[0054] Step S202 includes charging the central portion of the lower surface of the second substrate W2 while the peripheral portion of the lower surface of the second substrate W2 is attracted by the second holding portion 12 (see FIG. 10). The friction body moving portion 55 moves the friction body 50 in the horizontal direction while pressing it against the central portion of the lower surface of the second substrate W2. In addition, the movement drive portion 25 moves the second holding portion 12 together with the cup 20 in the horizontal direction. The movement direction of the friction body 50 intersects with the movement direction of the cup 20.

[0055] The friction body 50 rubs the central portion of the lower surface of the second substrate W2 to charge it. The friction body 50 is an example of a charging section. The central portion of the lower surface of the second substrate W2 and the friction body 50 are charged with opposite polarities. For example, when the lower surface of the second substrate W2 is made of an oxide film W2b and the friction body 50 is made of a resin such as PVA, the central portion of the lower surface of the second substrate W2 is charged with positive polarity and the friction body 50 is charged with negative polarity.

[0056] The lower nozzles 31, 32 supply an alkaline aqueous solution between the second substrate W2 held by the second holding unit 12 and the friction body 50. The alkaline aqueous solution is not particularly limited, but may be, for example, diluted ammonia water. Compared to pure water, the alkaline aqueous solution can promote frictional charging of the second substrate W2 and can increase the amount of charge on the second substrate W2. The alkaline aqueous solution can also negatively charge particles. Therefore, a large number of particles can be attached to the second substrate W2 by static electricity.

[0057] In order to suppress the occurrence of friction scratches, it is preferable that the lower nozzles 31 and 32 continuously supply the alkaline aqueous solution to the central part of the lower surface of the second substrate W2 from before the friction body 50 starts rubbing the second substrate W2 until the friction body 50 finishes rubbing the second substrate W2. After the lower nozzles 31 and 32 start supplying the alkaline aqueous solution, the friction body 50 starts rubbing the second substrate W2. Moreover, after the friction body 50 finishes rubbing the second substrate W2, the lower nozzles 31 and 32 stop supplying the alkaline aqueous solution.

[0058] An example of the distribution of electrostatic force obtained in step S202 is shown in Fig. 11. The inventors prepared a silicon wafer with a thermal oxide film formed on the entire surface as the second substrate, and confirmed that by rubbing the center of the lower surface of the second substrate with a PVA brush, the center of the lower surface of the second substrate becomes positively charged as shown in Fig. 11. Although not shown, it has also been confirmed that the larger the thickness of the thermal oxide film, the larger the electrostatic capacitance of the thermal oxide film and the larger the amount of charge on the second substrate.

[0059] Step S203 includes transferring the second substrate W2 from the second holding part 12 to the first holding part 11. First, as viewed from above, as shown in Fig. 2, the cup 20 is moved horizontally to a position where the center of the second substrate W2 overlaps with the center of the first holding part 11. During this time, the gas discharge ring 15 discharges gas onto the lower surface of the second substrate W2 to dry the lower surface of the second substrate W2.

[0060] Thereafter, the movement driver 25 lowers the cup 20, causing the second holder 12 to deliver the second substrate W2 to the first holder 11. The second holder 12 releases the suction of the peripheral portion of the lower surface of the second substrate W2, and the first holder 11 suctions the central portion of the lower surface of the second substrate W2. As a result, the central portion of the lower surface of the second substrate W2 comes into contact with the first holder 11, as shown in FIG.

[0061] At this time, the particles adhering to the first holding unit 11 and the central part of the lower surface of the second substrate W2 have opposite polarities. Therefore, the particles can be adhered to the second substrate W2 by static electricity, and can be removed from the first holding unit 11 together with the second substrate W2. This allows the first holding unit 11 to be efficiently cleaned.

[0062] In addition, by contacting the second substrate W2 with the first holding unit 11, the positive charge accumulated in the central portion of the lower surface of the second substrate W2 flows out to the first holding unit 11. As a result, the amount of charge in the central portion of the lower surface of the second substrate W2 decreases.

[0063] Step S204 includes charging the peripheral portion of the lower surface of the second substrate W2 while the first holding unit 11 is adsorbing the central portion of the lower surface of the second substrate W2 (see FIG. 13). The friction body moving unit 55 moves the friction body 50 in the horizontal direction while pressing it against the peripheral portion of the lower surface of the second substrate W2. In addition, the rotation driving unit 13 rotates the second substrate W2 together with the first holding unit 11. The friction body 50 rubs the peripheral portion of the lower surface of the second substrate W2 to charge it.

[0064] In step S204, flow electrification is dominant over frictional electrification. Flow electrification is a phenomenon in which a distribution of electrostatic force occurs when a liquid flows over a solid surface. In step S204, the rotary drive unit 13 rotates the second substrate W2, so that centrifugal force causes the alkaline aqueous solution to flow from the radially inner side to the radially outer side of the second substrate W2. In the process, flow electrification occurs, as described below. Note that in step S202, the rotary drive unit 13 does not rotate the second substrate W2, so flow electrification hardly occurs at all.

[0065] The lower nozzles 31, 32 supply an alkaline aqueous solution between the second substrate W2 held by the second holding portion 12 and the friction body 50. The alkaline aqueous solution is supplied between the center and peripheral portions of the lower surface of the second substrate W2, and flows to the peripheral portion of the lower surface of the second substrate W2 by centrifugal force. The alkaline aqueous solution contains negative ions and positive ions. At the supply position of the alkaline aqueous solution, the negative ions are easily adsorbed to the second substrate W2. The remaining positive ions are adsorbed to the peripheral portion of the lower surface of the second substrate W2. As a result, the electrostatic force distribution shown in FIG. 13 is generated.

[0066] Step S205 includes drying the second substrate W2. For example, the rotary drive unit 13 rotates the first holder 11 at high speed to shake off the processing liquid adhering to the second substrate W2.

[0067] Step S206 includes unloading the second substrate W2 from the inside to the outside of the processing device 124. First, the first holding unit 11 releases the suction of the second substrate W2, and the multiple lift pins 14 are raised, and the multiple lift pins 14 lift the second substrate W2 from the first holding unit 11. As a result, as shown in Fig. 14, the multiple lift pins 14 come into contact with the center of the lower surface of the second substrate W2.

[0068] At this time, the particles adhering to the multiple lift pins 14 and the central part of the lower surface of the second substrate W2 have opposite polarities. Therefore, the particles can be adhered to the second substrate W2 by static electricity, and can be removed from the lift pins 14 together with the second substrate W2. This allows the multiple lift pins 14 to be efficiently cleaned.

[0069] The transfer arm of the second transfer device 123 enters the processing device 124 from the outside to the inside, and waits above the cup 20. Next, the multiple lift pins 14 are lowered, and the multiple lift pins 14 hand over the second substrate W2 to the transfer arm. Note that instead of lowering the lift pins 14, the transfer arm may be raised. Thereafter, the transfer arm holds the second substrate W2 and exits the processing device 124.

[0070] At this time, the transfer arm comes into contact with the peripheral portion of the lower surface of the second substrate W2. The particles adhering to the transfer arm of the second transfer device 123 and the peripheral portion of the lower surface of the second substrate W2 have opposite polarities. Therefore, the particles can be attached to the second substrate W2 by static electricity, and can be taken out of the transfer arm together with the second substrate W2. This allows the transfer arm to be efficiently cleaned.

[0071] Fig. 15 shows an example of the distribution of electrostatic force obtained in step S206. The inventors prepared a silicon wafer having a thermal oxide film on the entire surface of the second substrate W2, and confirmed that by performing steps S202 to S206, the peripheral portion of the lower surface of the second substrate W2 becomes positively charged, as shown in Fig. 15. Although not shown, it has also been confirmed that the thicker the thermal oxide film is, the greater the electrostatic capacitance of the thermal oxide film is, and the greater the amount of charge on the second substrate W2 after step S206.

[0072] FIG. 16 shows an example of the distribution of electrostatic force obtained in step S206 when a third substrate was used instead of the second substrate W2. The third substrate had only a silicon wafer and had no thermal oxide film on its surface. As shown in FIG. 16, the charge amount was low over the entire radial direction of the third substrate. Comparing FIG. 15 and FIG. 16, it can be seen that the thermal oxide film contributes to charging.

[0073] An example of the number of particles adhering to the substrate W after the processing apparatus 124 is cleaned with the second substrate W2 or the third substrate will be described with reference to Fig. 17. In Fig. 17, the processing apparatus 124 is contaminated by processing a substrate W having 60,000 Si particles previously attached thereto in the processing apparatus 124. Thereafter, the processing apparatus 124 is repeatedly cleaned with the second substrate W2 or the third substrate, and the number of particles adhering to the substrate W is measured after the nth cleaning and before the (n+1)th cleaning.

[0074] 17, when the processing apparatus 124 was cleaned with the second substrate W2, the number of particles adhering to the substrate W was reduced compared to when the processing apparatus 124 was cleaned with the third substrate. The second substrate W2 has a thermal oxide film, unlike the third substrate. Therefore, the second substrate W2 is more likely to be charged than the third substrate, and is more likely to attract particles by static electricity, which is considered to enable the processing apparatus 124 to be cleaned efficiently.

[0075] Incidentally, the second substrate W2 is stored in the storage device 125 in this embodiment, but may be accommodated in a cassette placed on the placement table 111. In the latter case, the first transfer device 113 takes out the second substrate W2 from the cassette and transfers it to the transition device 121. Subsequently, the second transfer device 123 takes out the second substrate W2 from the transition device 121 and transfers it to the processing device 124. After that, the second substrate W2 is returned to the cassette in the reverse procedure. In this case, not only the transfer arm of the second transfer device 123 but also the transfer arm of the first transfer device 113 can be cleaned with the second substrate W2.

[0076] When the second substrate W2 is stored in the storage device 125, the storage device 125 may have a charging unit (not shown). The charging unit may charge the second substrate W2 by rubbing it, or may charge the second substrate W2 by irradiating it with ions. The second transport device 123 may sequentially bring the second substrate W2, which has been charged in the storage device 125, into contact with the multiple lift pins 14 and the second holding unit 12 in step S201. The contents of the present disclosure are also applicable to cleaning of the lift pins 14 and the second holding unit 12.

[0077] The processing device 124 may have a third holding part 16 as shown in FIG. 18, instead of the second holding part 12. The third holding part 16 grips the periphery of the substrate W. Naturally, the third holding part 16 can grip the second substrate W2 instead of the substrate W. The third holding part 16 is disposed above the first holding part 11. The third holding part 16 has a pair of movable claws 16A, 16B that sandwich and hold the substrate W. The pair of movable claws 16A, 16B are provided at an interval in the X-axis direction and are moved toward or away from each other. Note that a rotating top may be used instead of the movable claws 16A, 16B. Three or more rotating tops may be provided at intervals along the circumferential direction of the substrate W.

[0078] The multiple lift pins 14 move up and down around the first holding unit 11 to transfer the substrate W between the first holding unit 11 or the third holding unit 16 and the transport arm of the second transport device 123. The multiple lift pins 14 are mounted on a Y-axis slider 25a and are moved in the Y-axis direction together with the first holding unit 11. Note that the multiple lift pins 14 may not be mounted on the Y-axis slider 25a and may be provided in large numbers at intervals in the Y-axis direction.

[0079] The substrate W is transferred from the transfer arm of the second transfer device 123 to the lift pins 14, and then transferred from the lift pins 14 to the third holding unit 16. With the third holding unit 16 holding the periphery of the substrate W, a friction body (not shown) cleans the central portion of the lower surface of the substrate W. The substrate W is then transferred from the third holding unit 16 to the lift pins 14, and then transferred from the lift pins 14 to the first holding unit 11. With the first holding unit 11 holding the central portion of the lower surface of the substrate W, a friction body (not shown) cleans the peripheral portion of the lower surface of the substrate W. At this time, the substrate W is rotated together with the first holding unit 11.

[0080] In this modification, similarly to the above embodiment, it is possible to use the second substrate W2 to clean the first holding part 11, the third holding part 16, or the lift pins 14.

[0081] Next, an example of the wall will be described with reference to Figs. 19 and 20. The processing device 124 may have a wall 17 as shown in Figs. 19 and 20. The wall 17 is provided below the substrate W held by the first holding part 11 as shown in Fig. 20, and blocks the processing liquid discharged by the upper nozzle 33 toward the periphery of the substrate W from moving toward the first holding part 11. This can prevent the residue of the processing liquid from adhering to the first holding part 11 or the lower surface of the substrate W, and can prevent the generation of particles. This is particularly effective when the upper nozzle 33 is a two-fluid nozzle. The two-fluid nozzle crushes the processing liquid with a gas such as N2 gas, atomizes it, and sprays it.

[0082] 19, the wall portion 17 is provided radially inward of the periphery of the substrate W held by the first holding unit 11, and is provided radially outward of the substrate W from the gas discharge ring 15. The gas discharge ring 15 is provided radially inward of the substrate W from the lower nozzles 31, 32, and is provided radially outward of the substrate W from the first holding unit 11. As shown in FIG. 19, the wall portion 17 is provided radially inward of the periphery of the substrate W, and is provided radially outward of the substrate W from the gas discharge ring 15, so that the wall portion 17 can block the processing liquid discharged by the upper nozzle 33 toward the periphery of the substrate W from heading toward the first holding unit 11.

[0083] As shown in Fig. 19, when viewed from above, the entire wall portion 17 is disposed radially inward of the periphery of the substrate W held by the first holding portion 11. As shown in Fig. 20, the wall portion 17 only needs to be provided in the vicinity of the upper nozzle 33. However, the wall portion 17 may be provided in a ring shape along the periphery of the substrate W held by the first holding portion 11. In this embodiment, the wall portion 17 is flat plate-shaped, but may be curved plate-shaped. The wall portion 17 is provided to protrude upward from the upper surface of the exhaust pipe cover 47.

[0084] The upper surface of the exhaust pipe cover 47 is preferably positioned so as not to bounce back the processing liquid discharged by the upper nozzle 33 toward the peripheral edge of the substrate W. When viewed from above, the entire exhaust pipe cover 47 is preferably positioned radially inward of the peripheral edge of the substrate W held by the first holding part 11.

[0085] 20, the processing device 124 may have a second wall portion 18. The second wall portion 18 is provided below the substrate W held by the first holding portion 11, similar to the wall portion 17, but is provided radially outward of the substrate W than the wall portion 17. The second wall portion 18 is provided radially outward of the peripheral edge of the substrate W held by the first holding portion 11, and is provided radially inward of the substrate W than the cup 20.

[0086] The second wall portion 18 guides downward the processing liquid discharged by the upper nozzle 33 toward the periphery of the substrate W, on the inner side of the cup 20 in the radial direction of the substrate W. By narrowing the passage of the processing liquid, the flow of the downward air current can be strengthened. Therefore, the generation of an upward air current can be suppressed, and the flying up of particles can be suppressed.

[0087] 20, the second wall portion 18 may be provided only in the vicinity of the upper nozzle 33. However, the second wall portion 18 may be provided in a ring shape along the periphery of the substrate W held by the first holding portion 11. The second wall portion 18 is in the shape of a flat plate in this embodiment, but may be in the shape of a curved plate.

[0088] While the upper nozzle 33 is discharging the processing liquid toward the periphery of the substrate W, it is preferable to increase the flow rate at which the lower nozzles 31, 32 discharge the processing liquid compared to while the friction body 50 is rubbing the center of the underside of the substrate W. By discharging the processing liquid at a high flow rate from the lower nozzles 31, 32 while the upper nozzle 33 is discharging the processing liquid toward the periphery of the substrate W, it is possible to prevent the processing liquid discharged by the upper nozzle 33 from flowing around onto the underside of the substrate W and to prevent particles from adhering to the gas discharge ring 15 or the first holding unit 11.

[0089] Furthermore, while the upper nozzle 33 is discharging the processing liquid toward the periphery of the substrate W, it is preferable that the gas discharge ring 15 reduces the gas discharge flow rate compared to while the friction body 50 is rubbing the center of the lower surface of the substrate W. By discharging gas at a high flow rate from the gas discharge ring 15 while the friction body 50 is rubbing the center of the lower surface of the substrate W, it is possible to prevent the processing liquid discharged by the lower nozzles 31 and 32 from adhering to the gas discharge ring 15 or the first holding unit 11, and to prevent particles from adhering to the gas discharge ring 15 or the first holding unit 11.

[0090] Although the embodiments of the substrate processing apparatus and substrate processing method according to the present disclosure have been described above, the present disclosure is not limited to the above-mentioned embodiments. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the claims. These naturally fall within the technical scope of the present disclosure. [Explanation of symbols]

[0091] 100 Substrate processing apparatus 124 Processing equipment (processing unit) 190 Control device (control unit) 11 1st holding part 12 Second holding part 13 Rotation drive unit 50 Friction body (charging part) W substrate W2 Second board

Claims

1. A substrate processing apparatus comprising a processing section for processing a substrate with a processing liquid, the processing section having a holding section for holding the substrate horizontally, the holding section including a first holding section contacting a center of a lower surface of the substrate, the processing section having a rotation drive section for rotating the first holding section around a vertical rotation axis, a charging unit that charges a second substrate prepared separately from the substrate; a control unit that performs control to bring the second substrate charged by the charging unit into contact with the first holding unit; The substrate processing apparatus includes:

2. The substrate processing apparatus according to claim 1 , wherein the charging section includes a friction body that rubs a lower surface of the second substrate held by the holding section.

3. The substrate processing apparatus according to claim 2 , further comprising a lower nozzle that supplies an alkaline aqueous solution between the second substrate held by the holding part and the friction body.

4. the holding portion includes a second holding portion that contacts a lower surface of the second substrate on a radially outer side of the substrate compared to the first holding portion, The control unit is rubbing the center of the lower surface of the second substrate with the friction body while the second substrate is held horizontally by the second holding unit; supplying the alkaline aqueous solution to the lower surface of the second substrate continuously from before the rubbing is started until after the rubbing is finished; drying the lower surface of the second substrate with a gas after the alkaline aqueous solution is supplied; After the drying, contacting the center of the lower surface of the second substrate with the first holding part; The substrate processing apparatus according to claim 3 , further comprising:

5. the holding portion includes a third holding portion that grips a peripheral edge of the substrate, The control unit is rubbing the center of the lower surface of the second substrate with the friction body while the second substrate is held horizontally by the third holding unit; supplying the alkaline aqueous solution to the lower surface of the second substrate continuously from before the rubbing is started until after the rubbing is finished; drying the lower surface of the second substrate with a gas after the alkaline aqueous solution is supplied; After the drying, contacting the center of the lower surface of the second substrate with the first holding part; The substrate processing apparatus according to claim 3 , further comprising:

6. the substrate processing apparatus includes a storage unit that stores the second substrate, and a transport unit that transports the second substrate between the storage unit and the processing unit, The substrate processing apparatus according to claim 1, wherein the charging section charges the second substrate in the storage section.

7. 6. The substrate processing apparatus according to claim 1, wherein the second substrate has an oxide film on at least a lower surface thereof.

8. The holding portion includes a plurality of lift pins provided around the first holding portion, 6. The substrate processing apparatus according to claim 1, wherein the control unit brings the second substrate, which has been charged by the charging unit, into contact with the lift pins.

9. a first holding portion that contacts the center of the lower surface of the substrate and holds the substrate horizontally; a rotation drive unit that rotates the first holding unit around a vertical rotation axis; an upper nozzle for supplying a processing liquid to an upper surface of the substrate held by the first holding unit; a lower nozzle for supplying a processing liquid to a lower surface of the substrate held by the first holding unit; a gas discharge unit that is provided radially inward of the lower nozzle and radially outward of the substrate than the first holding unit, and that discharges a gas toward a lower surface of the substrate held by the first holding unit; a cup surrounding a periphery of the substrate held by the first holding portion; a wall portion provided below the substrate held by the first holding portion and configured to block the processing liquid ejected by the upper nozzle toward the periphery of the substrate from heading toward the first holding portion; Equipped with The wall portion is provided radially inward of the substrate relative to a peripheral edge of the substrate held by the first holding portion, and is provided radially outward of the substrate relative to the gas discharge portion.

10. 1. A method of processing a substrate, comprising processing a substrate using a substrate processing apparatus, comprising: The substrate processing apparatus includes a processing section for processing a substrate with a processing liquid, the processing section having a holding section for holding the substrate horizontally, the holding section including a first holding section contacting a center of a lower surface of the substrate, the processing section having a rotation drive section for rotating the first holding section around a vertical rotation axis, The substrate processing method includes charging a second substrate prepared separately from the substrate, and contacting the charged second substrate with the first holding part.

11. The substrate processing method according to claim 10 , wherein charging the second substrate includes rubbing a lower surface of the second substrate held by the holder with a friction body.

12. The substrate processing method according to claim 11 , further comprising: supplying an alkaline aqueous solution between the second substrate held by the holder and the friction body.

13. the holding portion includes a second holding portion that contacts a lower surface of the second substrate on a radially outer side of the substrate compared to the first holding portion, The substrate processing method includes: rubbing the center of the lower surface of the second substrate with the friction body while the second substrate is held horizontally by the second holding unit; supplying the alkaline aqueous solution to the lower surface of the second substrate continuously from before the rubbing is started until after the rubbing is finished; drying the lower surface of the second substrate with a gas after the alkaline aqueous solution is supplied; After the drying, contacting the center of the lower surface of the second substrate with the first holding part; The method of claim 12 , comprising:

14. the holding portion includes a third holding portion that grips a peripheral edge of the substrate, The substrate processing method includes: rubbing the center of the lower surface of the second substrate with the friction body while the second substrate is held horizontally by the third holding unit; supplying the alkaline aqueous solution to the lower surface of the second substrate continuously from before the rubbing is started until after the rubbing is finished; drying the lower surface of the second substrate with a gas after the alkaline aqueous solution is supplied; After the drying, contacting the center of the lower surface of the second substrate with the first holding part; The method of claim 12 , comprising:

15. the substrate processing apparatus includes a storage unit that stores the second substrate, and a transport unit that transports the second substrate between the storage unit and the processing unit, The substrate processing method according to any one of claims 10 to 14, further comprising charging the second substrate in the storage section.

16. The substrate processing method according to any one of claims 10 to 14, wherein the second substrate has an oxide film on at least a lower surface thereof.

17. The holding portion includes a plurality of lift pins provided around the first holding portion, The substrate processing method according to any one of claims 10 to 14, further comprising contacting the charged second substrate with the lift pins.

18. A method of processing a substrate, comprising processing a substrate using the substrate processing apparatus of claim 9.

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