Substrate processing apparatus and substrate processing method

Abstract

A substrate processing apparatus and a substrate processing method are provided. The substrate processing apparatus includes a substrate holding portion capable of holding a substrate; a rotation drive portion that rotates the substrate holding portion around a rotation axis; a processing liquid nozzle that discharges a processing liquid to a peripheral portion of the substrate; and a gas nozzle that discharges a gas to the processing liquid during a period from a time when the processing liquid is discharged from a discharge port of the processing liquid nozzle to a time when a landing point on the substrate is reached. According to the present invention, reattachment of the processing liquid to the substrate after detachment from the substrate can be prevented or suppressed.

Description

Technical Field

[0001] This invention relates to a substrate processing apparatus and a substrate processing method. Background Technology

[0002] In the manufacture of semiconductor devices, a step called "tilt etching" is performed, in which unwanted films on the periphery of a circular substrate such as a semiconductor wafer are removed by wet etching with a chemical solution. Patent Document 1 discloses an apparatus for performing tilt etching. The tilt etching apparatus disclosed in Patent Document 1 includes: a vacuum chuck that holds the substrate in a horizontal position and rotates it about a vertical axis; and a nozzle that supplies etching solution to the periphery of the rotating substrate. In addition, the tilt etching apparatus disclosed in Patent Document 1 has an annular protective wall to prevent the processing solution that has detached from the substrate after being supplied to the substrate from re-adhering to the substrate.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent document 1: Japanese Patent Application Publication No. 2014-086638. Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] This invention provides a technique to prevent or suppress the re-adhesion of a processing liquid that has detached from a substrate onto the substrate.

[0008] Technical means for solving problems

[0009] One embodiment of the substrate processing apparatus includes: a substrate holding portion capable of holding a substrate; a rotation drive portion for rotating the substrate holding portion about a rotation axis; a processing liquid nozzle for discharging processing liquid to the periphery of the substrate; and a gas nozzle that discharging gas into the processing liquid from the moment the processing liquid is released from the release port of the processing liquid nozzle until the moment it reaches a landing point on the substrate.

[0010] Invention Effects

[0011] According to the present invention, it is possible to prevent or suppress the re-adhesion of the treatment liquid after it has detached from the substrate. Attached Figure Description

[0012] Figure 1 This is a schematic cross-sectional plan view of a substrate processing apparatus according to one embodiment.

[0013] Figure 2 yes Figure 1 A schematic longitudinal cross-sectional view of the processing unit of the substrate processing device.

[0014] Figure 3 is a diagram explaining liquid processing performed by the processing unit.

[0015] Figure 4 is a diagram explaining liquid processing performed by the processing unit.

[0016] Figure 5 is a diagram explaining liquid processing performed by the processing unit.

[0017] Figure 6 is a diagram explaining liquid processing performed by the processing unit.

[0018] Figure 7A is a perspective view explaining various parameters associated with release of liquid chemical from a liquid chemical nozzle.

[0019] Figure 7B is a plan view explaining the action after the liquid chemical released from the liquid chemical nozzle lands on the substrate.

[0020] Figure 8A is a plan view explaining the first mode of reattachment prevention of the liquid chemical after separation.

[0021] Figure 8B is a side view explaining the first mode of reattachment prevention of the liquid chemical after separation.

[0022] Figure 9A is a plan view explaining the second mode of reattachment prevention of the liquid chemical after separation.

[0023] Figure 9B is a side view explaining the second mode of reattachment prevention of the liquid chemical after separation.

[0024] Figure 10A is a plan view explaining the third mode of reattachment prevention of the liquid chemical after separation.

[0025] Figure 10B is a side view explaining the third mode of reattachment prevention of the liquid chemical after separation.

[0026] Figure 11 is a side view explaining the fourth mode of reattachment prevention of the liquid chemical after separation.

[0027] Figure 12 is a chart explaining experimental results.

[0028] Figure 13 is a chart explaining experimental results.

[0029] BRIEF DESCRIPTION OF DRAWINGS

[0030] 31 substrate holding section

[0031] 32 rotation driving section

[0032] 41A processing liquid (chemical liquid) nozzle

[0033] PF landing point

[0034] 43A gas nozzle DETAILED DESCRIPTION

[0035] An embodiment of a substrate processing apparatus will be described below with reference to the drawings.

[0036] Figure 1 is a diagram showing the schematic configuration of a substrate processing system according to the present embodiment. Hereinafter, in order to make the positional relationship clear, X, Y, and Z axes orthogonal to each other are defined, with the positive direction of the Z axis being the vertical upward direction.

[0037] As shown in Figure 1 , the substrate processing system 1 includes an in-out station 2 and a processing station 3. The in-out station 2 and the processing station 3 are arranged adjacent to each other.

[0038] The in-out station 2 includes a carrier placement section 11 and a transport section 12. The carrier placement section 11 is capable of placing a plurality of carriers C for housing a plurality of substrates, i.e., semiconductor wafers (hereinafter, wafers W) in the present embodiment, in a horizontal state.

[0039] The transport section 12 is arranged adjacent to the carrier placement section 11 and has a substrate transport device 13 and a handover section 14 inside. The substrate transport device 13 has a wafer holding mechanism that holds the wafers W. In addition, the substrate transport device 13 is capable of moving in the horizontal and vertical directions and rotating about the vertical axis, and performs transport of the wafers W between the carriers C and the handover section 14 using the wafer holding mechanism.

[0040] The processing station 3 is arranged adjacent to the transport section 12. The processing station 3 includes a transport section 15 and a plurality of processing units 16. The plurality of processing units 16 are arranged on both sides of the transport section 15.

[0041] The transport section 15 has a substrate transport device 17 inside. The substrate transport device 17 has a wafer holding mechanism that holds the wafers W. In addition, the substrate transport device 17 is capable of moving in the horizontal and vertical directions and rotating about the vertical axis, and performs transport of the wafers W between the handover section 14 and the processing units 16 using the wafer holding mechanism.

[0042] The processing units 16 perform prescribed substrate processing on the wafers W transported by the substrate transport device 17.

[0043] Further, the substrate processing system 1 includes a control device 4. The control device 4 is, for example, a computer, and includes a control section 18 and a storage section 19. In the storage section 19, a program for controlling various processes performed in the substrate processing system 1 is stored. The control section 18 controls the operation of the substrate processing system 1 by reading and executing the program stored in the storage section 19.

[0044] Further, the above-mentioned program is a program stored in a storage medium readable by a computer, and can be a program installed from the storage medium to the storage section 19 of the control device 4. As the storage medium readable by a computer, for example, there are a hard disk (HD), a floppy disk (FD), a compact disc (CD), a magneto-optical disk (MO), a memory card, and the like.

[0045] In the substrate processing system 1 configured as described above, first, the substrate transport device 13 of the load lock station 2 takes out a wafer W from the carrier C placed on the carrier placement section 11, and places the taken-out wafer W on the handoff section 14. The wafer W placed on the handoff section 14 is taken out from the handoff section 14 by the substrate transport device 17 of the processing station 3, and is fed into the processing unit 16.

[0046] The wafer W fed into the processing unit 16 is processed by the processing unit 16, and is fed out from the processing unit 16 by the substrate transport device 17, and is placed on the handoff section 14. Then, the processed wafer W placed on the handoff section 14 is fed back to the carrier C of the carrier placement section 11 by the substrate transport device 13.

[0047] Next, the processing unit 16 will be described with reference to Figure 2 to FIG. 8. Figure 2 is a diagram showing the schematic configuration of the processing unit 16.

[0048] The processing unit 16 has a chamber (housing) 20, and the substrate holding mechanism 30, the processing fluid supply section 40, and the recovery cup 50 are housed in the chamber 20. The FFU (Fan Filter Unit) 21 is provided at the top of the chamber 20. The FFU 21 forms an air current downward in the chamber 20.

[0049] The substrate holding rotation mechanism 30 includes a substrate holding section 31 that holds the wafer W in a horizontal posture, and a rotation drive section 32 that rotates the substrate holding section 31 about a vertical axis (rotation axis). The substrate holding section 31 is formed as a vacuum chamber that adsorbs the back central portion of the wafer W to hold the wafer W. The rotation drive section 32 is formed as a motor, and the upper end of the rotation shaft of the motor is connected to the vacuum chuck. By operating the motor, the wafer W can be rotated about the vertical axis.

[0050] The processing fluid supply section 40 supplies a processing fluid such as a processing liquid, a processing gas, and the like to the peripheral portion of the wafer W. The processing fluid supply section 40 has a chemical liquid supply section 41, a cleaning liquid supply section 42, and a gas supply section 43.

[0051] The chemical liquid supply section 41 includes a chemical liquid nozzle 41A, a chemical liquid nozzle drive mechanism 41B, and a chemical liquid supply mechanism 41C. The chemical liquid nozzle drive mechanism 41B is capable of moving the chemical liquid nozzle 41A between a processing position (a position for supplying a chemical liquid to the wafer W) and a standby position, and changing the orientation of the chemical liquid nozzle 41A (details will be described later). The chemical liquid supply mechanism 41C supplies a chemical liquid (for example, an etching liquid) to the chemical liquid nozzle 41A. Although not illustrated in detail, the chemical liquid supply mechanism 41C is constituted by a pipe (a line) connected to a chemical liquid supply source of a factory facility, a tank, and the like, and a flow control device (an on-off valve, a flow meter, a flow control valve, and the like) provided to the pipe.

[0052] The cleaning liquid supply section 42 includes a cleaning nozzle 42A, a cleaning nozzle drive mechanism 42B, and a cleaning liquid supply mechanism 42C. The cleaning nozzle drive mechanism 42B is capable of moving the cleaning nozzle 42A between a processing position (a position for supplying a processing liquid to the wafer W) and a standby position, and changing the orientation of the cleaning nozzle 42A (details will be described later). The cleaning liquid supply mechanism 42C supplies a cleaning liquid (for example, DIW) to the cleaning nozzle 42A. Although not illustrated in detail, the cleaning liquid supply mechanism 42C is constituted by a pipe (a line) connected to a cleaning liquid supply source of a factory facility, a tank, and the like, and a flow control device (an on-off valve, a flow meter, a flow control valve, and the like) provided to the pipe.

[0053] The gas supply section 43 includes a gas nozzle 43A, a gas nozzle drive mechanism 43B, and a gas supply mechanism 43C. The gas nozzle drive mechanism 43B is capable of moving the gas nozzle 43A between a processing position (a position for supplying a gas to the wafer W) and a standby position, and changing the orientation of the gas nozzle 43A (details will be described later). The gas supply mechanism 43C supplies a gas (for example, nitrogen gas) to the gas nozzle 43A. Although not illustrated in detail, the chemical liquid supply mechanism 43C is constituted by a pipe (a line) connected to a gas supply source of a factory facility, a tank, and the like, and a flow control device (an on-off valve, a flow meter, a flow control valve, and the like) provided to the pipe.

[0054] The chemical liquid nozzle 41A and the cleaning nozzle 42A have a release port that opens to the obliquely downward direction when becoming a standing posture.

[0055] The configuration of the liquid supply unit 41, the cleaning fluid supply unit 42, and the gas supply unit 43 is not limited to the example shown in the figure. The configuration of the supply units 41, 42, and 43 is arbitrary as long as it enables the supply of the processing fluid (liquid incident angle θ, φ, gas release angle α, β, etc., described later) to the periphery of the wafer W. The nozzle drive mechanisms 41B, 42B, and 43B preferably have dual-axis or multi-axis nozzle orientation control functions, enabling adjustment of all liquid incident angles θ, φ, and gas release angles α, β.

[0056] In addition, Figure 2 Although the heights of the liquid supply unit 41, the cleaning fluid supply unit 42, and the gas supply unit 43 are different, this is to show the supply units 41, 42, and 43 simultaneously in the attached drawing; in reality, this may not be the case.

[0057] The liquid receiving cup 50 is configured to surround the substrate holding portion 31 to collect the processing liquid that has scattered (detached) from the rotating wafer W. A drain port 51 and an exhaust port 52 are formed at the bottom of the liquid receiving cup 50. The processing liquid collected by the liquid receiving cup 50 is discharged from the drain port 51 to the outside of the processing unit 16. The atmosphere inside the liquid receiving cup 50 is drawn out through the exhaust port 52 and discharged to the outside of the processing unit 16. Along with the drawing out of the atmosphere inside the liquid receiving cup 50, the atmosphere in the space above the liquid receiving cup 50 (clean gas released from the FFU 21) is drawn into the liquid receiving cup 50 through the upper opening of the liquid receiving cup 50.

[0058] Next, refer to Figures 3-6 This section briefly explains the liquid treatment performed by the processing unit 16 without using the gas nozzle 43A. Figures 3-6 In the diagram, (A) is a three-dimensional view, (B) is a side view, and (C) is a two-dimensional view.

[0059] like Figure 3 As shown, the etching solution (CHM) for tilting etching is released from the solution nozzle 41A, which is in a standby position (e.g., a position radially outward from the periphery WE of the wafer W). After the solution release flow rate stabilizes, the solution nozzle 41A is moved to the processing position, and the solution falls onto the periphery of the wafer W, that is, a position radially inward from the periphery WE of the wafer W.

[0060] like Figure 4 As shown, using a chemical solution adhering to the periphery of a rotating wafer W from a nozzle 41A, the portion of the etching target film on the surface of the wafer W that is in contact with the chemical solution is removed by etching. Furthermore, at this time, the chemical solution either diffuses to the periphery WE of the wafer W and then detaches from the outside of the wafer W, or bounces off the wafer W at the moment of impact. See the section described later for details. Figure 7B Explanation.

[0061] After the desired area of the periphery of the wafer W is etched, as shown in Figure 5 the cleaning nozzle 42A that releases cleaning liquid (e.g., DIW) outward of the periphery of the wafer W is moved upward of the wafer W instead.

[0062] Then, as shown in Figure 6 the cleaning liquid is released from the cleaning nozzle 42A toward the wafer W in such a manner that the landing point is located slightly inward of the landing point of the chemical liquid, and cleaning processing is performed. At this time, the behavior after the landing of the cleaning liquid is substantially the same as the behavior after the landing of the chemical liquid.

[0063] After the end of the cleaning processing, the cleaning nozzle 42A is retracted outward of the periphery of the wafer W, and the wafer W is continuously rotated to perform spin-drying of the wafer W. At this time, the gas released from the gas nozzle 43A can be used to promote drying.

[0064] In the chemical liquid processing and the cleaning processing, in order to prevent liquid from going around from the surface of the wafer W to the back surface, cleaning liquid or shielding gas (e.g., nitrogen gas) can be supplied to the back surface periphery of the wafer W.

[0065] When the chemical liquid scattered (disengaged) from the wafer W in the above-described chemical liquid processing re-attaches to the wafer W, it becomes a cause of particles. Hereinafter, a method of preventing re-attachment of the chemical liquid to the wafer W using the gas nozzle 43A will be described. Also, in the case where the cleaning liquid disengaged from the wafer W in the cleaning processing re-attaches to the wafer W, it also becomes particles, and therefore, the same method is implemented using the gas nozzle 43A in the cleaning processing as well.

[0066] Before describing the disengaged liquid re-attachment prevention method, reference will be made to Figure 7A to describe various parameters that define the flight trajectory of the chemical liquid (CHM) released from the chemical liquid nozzle 41A.

[0067] In Figure 7A , the definitions of the respective symbols are as follows. The definitions of the following symbols are the same in the drawings other than Figure 7A .

[0068] AX: Rotational axis of the wafer W.

[0069] WC: Intersection of the surface of the wafer W and the rotational axis AX and (rotational center of the wafer W in the surface of the wafer W).

[0070] WE: Outermost periphery of the wafer W (also referred to as APEX).

[0071] PE: Release point of the chemical liquid (release port of the chemical liquid nozzle 41A).

[0072] PF: landing point of the chemical liquid on the wafer W surface.

[0073] ω: rotation direction of the wafer W.

[0074] r: distance from the rotation center WC to the landing point PF.

[0075] LT: tangent line of the landing point PF on the circumference of the circle having a radius r centered at the rotation center WC (they are in the same plane as the wafer W surface).

[0076] VC: vector indicating the flight trajectory of the chemical liquid from the release point PE toward the landing point PF.

[0077] VT: tangent direction component of the vector VC indicating the motion of the chemical liquid at the landing point PF (in addition, the direction of the vector VT is preferably the same as the rotation direction ω of the wafer W. When opposite to the rotation direction ω, it is difficult to control the splashing (jumping) of the chemical liquid at the landing point PF.).

[0078] F1: foot of the perpendicular line LP1 from the release point PE to the wafer W surface.

[0079] F2: foot of the perpendicular line LP2 from the foot F1 to the tangent line LT.

[0080] θ: angle of the line segment F1PF to the line segment F2PF (referred to as "1st liquid incidence angle θ").

[0081] φ: angle of the line segment PEPF to the line segment F1PF (referred to as "2nd liquid incidence angle φ").

[0082] VS: vector indicating the direction of the main body of the chemical liquid CHM that has just landed on the landing point PF and is flying outward (immediately separates) from the wafer W.

[0083] F3: foot of the perpendicular line from the point on the vector VS to the plane including the wafer W surface.

[0084] θS: angle of the tangent line LT to the line segment PFF3 (referred to as "1st liquid separation angle θS").

[0085] φS: angle of the line segment PFF3 to the vector VS (referred to as "2nd liquid separation angle φS").

[0086] Figure 7B is a diagram illustrating the separation of the chemical liquid from the wafer W. The chemical liquid that has landed on the peripheral portion of the rotating wafer W after being released from the chemical liquid nozzle 41A spreads to the wafer W peripheral edge WE by the centrifugal force, and separates from the wafer W peripheral edge WE or its vicinity in the state of a droplet by the centrifugal force. This phenomenon is referred to as "spreading and then separating". In the present embodiment, the 1st liquid incidence angle θ and the 2nd liquid incidence angle φ are set to be within the range of 0 to 90 degrees, and the 1st liquid separation angle θS and the 2nd liquid separation angle φS are set to be within the range of 0 to 90 degrees. Figure 7BIn the figure, the liquid droplet immediately before the detachment after the diffusion is denoted by the reference symbol Ldl, and the liquid droplet immediately after the detachment after the diffusion is denoted by the reference symbol Ld2. The size of the liquid droplet generated in association with the detachment after the diffusion is large.

[0087] A part of the liquid medicine landing on the landing point PF of the peripheral portion of the wafer W directly bounces on the surface of the wafer, does not spread to the periphery of the wafer W, and directly detaches from the wafer W after the landing to scatter as a liquid droplet. This phenomenon is called "immediate detachment". The liquid medicine after the immediate detachment scatters as a minute liquid droplet (Lm) of a relatively small size in the direction indicated by the arrow VS (the outer side of the wafer W) and in the direction indicated by the arrow Vsa (the inner side of the wafer W). Figure 7B The minute liquid droplet scatters to a region having a certain degree of width centered on the arrow VS and the arrow Vsa. The arrow VS and the arrow Vsa indicate the direction of the main body of the scattered liquid droplet.

[0088] The four detachment liquid reattachment prevention methods using the gas nozzle 43A described below relate to the reattachment prevention of the liquid droplet of the immediate detachment.

[0089] <1st Method>

[0090] First, the 1st method is described with reference to Figure 8A and Figure 8B

[0091] In the description and the drawings,

[0092] The landing point PF of the liquid medicine when the gas nozzle 43A does not release gas (when the gas is not released) is denoted by "PFi",

[0093] The landing point PF of the liquid medicine when the gas nozzle 43A releases gas (when the gas is released) is denoted by "PFm",

[0094] The vector VC indicating the flight trajectory of the liquid medicine when the gas is not released is denoted by "VCi",

[0095] The vector VC indicating the flight trajectory of the liquid medicine when the gas is released is denoted by "VCm",

[0096] The vector VS of the main body of the liquid medicine of the immediate detachment going to the outer side of the wafer when the gas is not released is denoted by "VSi",

[0097] The vector VS of the main body of the liquid medicine of the immediate detachment going to the outer side of the wafer when the gas is released is denoted by "VSm",

[0098] The value of the 1st liquid incident angle θ when the gas is not released is denoted by "θi",

[0099] The value of the 1st liquid incident angle θ when the gas is released is denoted by "θm",​

[0100] The value of the first liquid separation angle θS when the gas is not released is denoted as "θSi",

[0101] The value of the first liquid separation angle θS when the gas is released is denoted as "θSm",

[0102] The value of the second liquid incidence angle φ when the gas is not released is denoted as "φi",

[0103] The value of the second liquid incidence angle φ when the gas is released is denoted as "φm",

[0104] The value of the second liquid separation angle φS when the gas is not released is denoted as "φSi",

[0105] The value of the second liquid separation angle φS when the gas is released is denoted as "φSm".

[0106] The gas nozzle 43A can satisfy the following conditions. The gas released from the gas nozzle 43A diverts the chemical liquid (CHM) in the middle of the flight of the chemical liquid from the release port (release point PE) of the chemical liquid nozzle 41A to the landing point PFi on the wafer W. That is, the flight trajectory VC of the chemical liquid (a straight line connecting the release point PE of the chemical liquid to the landing point PFi) when the gas is not released from the gas nozzle 43A is bent (VCi→VCm) by the gas released from the gas nozzle 43A. Thereby, the value of the first liquid incidence angle θ is made larger from θi to θm (θi<θm) (landing condition 1). In addition, the value of the second liquid incidence angle φ is made smaller from φi to φm (φi>φm) (landing condition 2). Furthermore, the orientation of the main body of the gas released from the gas nozzle 43A is indicated by an arrow G.

[0107] In one embodiment, the gas nozzle 43A can be configured such that the axis of the release port of the gas nozzle 43A intersects the flight trajectory VC of the chemical liquid from the release point PE of the chemical liquid to the landing point PF. In addition, the radial position of the release port of the gas nozzle 43A (corresponding to the distance in the radial direction of the wafer W from the center of rotation WC of the wafer W when viewed from above. The same applies hereinafter.) can be configured on the inner side in the radial direction than the radial position of the release point PE of the chemical liquid. In addition, the release port of the gas nozzle 43A can be configured at a position lower in height than the release port of the chemical liquid nozzle 41A.

[0108] When the first liquid incidence angle θ is increased, the first liquid separation angle θS also increases (θSi→θSm) due to the inertial force acting on the liquid. It is preferable that the direction of liquid separation be close to the radial direction of the wafer W (i.e., |90deg-θS| (the absolute value of 90deg-θS) be close to zero deg). In this case, the liquid droplets that separate immediately from the peripheral edge portion of the wafer W leave the vicinity of the peripheral edge WE of the wafer W in a short time, and the possibility of the liquid droplets that separate immediately from re-attaching to the wafer W is reduced. As |90deg-θS| increases (especially, in the case where 90deg-θS is positive), the time for which the liquid droplets that separate immediately float in the vicinity of the peripheral edge WE of the wafer W becomes longer, and the possibility of the liquid droplets that separate immediately re-attaching to the wafer W becomes higher.

[0109] That is, as described above, by turning the liquid in flight (after being released and before landing) by gas to make the first liquid separation angle θS close to 90 degrees (θSi→θSm), the possibility of the liquid droplets of the liquid that separates immediately re-attaching to the wafer W can be reduced. Thus, the re-attachment of the liquid droplets of the liquid that separates immediately can be practically suppressed.

[0110] Figure 12 is a graph showing the results of an experiment investigating the relationship between the first liquid incidence angle θ and the number of particles. From this graph, it is known that the number of particles decreases as the first liquid incidence angle θ increases. As described above, as the first liquid incidence angle θ increases, the first liquid separation angle θS also increases, and as the first liquid separation angle θS increases, the number of particles decreases.

[0111] In addition, the greater the second liquid incidence angle φ, the greater the impact at the time of landing, and the greater the amount of liquid droplets that bounce back at the time of landing (i.e., liquid droplets that separate immediately). That is, by reducing the second liquid incidence angle φ (φi→φm), the amount of liquid droplets that separate immediately can be reduced. Instead, the amount of liquid droplets that separate after diffusion increases. Furthermore, the liquid droplets that separate after diffusion separate from the wafer W in the horizontal direction or slightly below the horizontal direction from the peripheral edge of the wafer W, and in addition, the size is also relatively large. Therefore, there is no problem that the liquid droplets that separate after diffusion float for a long time above the surface of the wafer W, and it is difficult to become a cause of the generation of particles due to re-attachment.

[0112] A part of the liquid that separates immediately after separation, as previously described with reference to Figure 7B , is scattered in the area centered on the arrow VSa (an area inside the radial direction from the circle including the landing point PF) in Figure 8A . However, as minute liquid droplets, the amount of such liquid droplets can also be reduced by reducing the second liquid incidence angle φ. In addition, by increasing the first liquid incidence angle θ to make the direction of the arrow VSa close to the tangential direction (LT, defined with reference to Figure 7A ) at the landing point PF. Therefore, the possibility of the liquid droplets that are scattered in the direction of the arrow VSa re-attaching to the surface of the wafer W is reduced.

[0113] As described above, as shown in Figure 8B , the flying liquid is diverted by the gas, and thus, even if the 2nd liquid incident angle φ is reduced, the amount of the liquid itself that instantaneously separates from the wafer W can be reduced. Therefore, the possibility that the liquid droplet that separates from the wafer re-attaches to the wafer W can be further reduced.

[0114] Further, by reducing the 2nd liquid incident angle φ, the 2nd liquid separation angle φS also becomes small Figure 8B (φSi→φSm). That is, the direction of the instantaneous separation approaches the horizontal direction. Thus, the amount of the liquid droplet that floats upward compared to the plane including the surface of the wafer W to which the possibility of re-attachment is high is reduced. Therefore, the possibility that the liquid droplet that separates from the wafer re-attaches to the wafer W can be further reduced.

[0115] It is also possible to satisfy only one of the above-described landing conditions 1 and 2 with the gas released from the gas nozzle 43A, but it is preferable to satisfy both.

[0116] Further, in the area around the arrow G (the arrow G indicates the main body of the gas) shown in Figure 8A and Figure 8B , a flow of the gas that flows in a direction substantially parallel to the arrow G is also generated. The flow rate of the gas becomes smaller the farther it is from the arrow G, but the path of the liquid droplet that instantaneously separates has an influence on the landing point PF. That is, the gas released from the gas nozzle 43A not only diverts the liquid CHM in flight, but also functions to blow the liquid droplet that instantaneously separates from the wafer W to the radial direction outside of the wafer W. Therefore, the liquid droplet that separates from the wafer W immediately moves away from the wafer W, and thus, the possibility that the liquid droplet that instantaneously separates re-attaches to the wafer W can be further reduced.

[0117] Further, the closer the direction of the main body G of the gas and the direction (VCm) of the flight trajectory of the liquid diverted by the gas (the flight trajectory after the diversion), the greater the blowing effect of the gas on the separated liquid. For example, by increasing the flow rate of the gas released from the gas nozzle 43A or reducing the flow rate of the liquid released from the liquid nozzle 41A, the direction of the main body G of the gas and the direction (VCm) of the flight trajectory of the liquid diverted by the gas can be made closer.

[0118] Further, the liquid droplet indicated by the arrow VSa of the above-described Figure 8A is also blown to the radial direction outside of the wafer W by the gas released from the gas nozzle 43A. Therefore, the possibility that the liquid droplet that separates from the wafer re-attaches to the wafer W can be further reduced. The effect is greater the closer the direction of the main body G of the gas and the direction (VCm) of the flight trajectory of the liquid diverted by the gas (the flight trajectory after the diversion).

[0119] Further, in the case where the liquid nozzle 41A and the gas nozzle 43A areFigure 2 The processing unit 16 shown in the configuration is such that, as described above, the cleaning gas released downward from the FFU 21 toward the wafer W is introduced into the liquid receiving cup 50. At this time, the cleaning gas flows approximately to the outer radius side of the wafer W after flowing along the surface of the peripheral portion of the wafer W, and then departs from the area on the outer radius side of the wafer, and thereafter, flows downward (refer to arrow F). By this flow of the cleaning gas, it is also possible to prevent the liquid droplets that have departed from the wafer W from re-attaching to the wafer. Therefore, it is preferable that the gas be released from the gas nozzle 43A so as not to be opposite to the flow of the cleaning gas. Figure 2 The processing unit 16 shown in the configuration is such that, as described above, the cleaning gas released downward from the FFU 21 toward the wafer W is introduced into the liquid receiving cup 50. At this time, the cleaning gas flows approximately to the outer radius side of the wafer W after flowing along the surface of the peripheral portion of the wafer W, and then departs from the area on the outer radius side of the wafer, and thereafter, flows downward (refer to arrow F). By this flow of the cleaning gas, it is also possible to prevent the liquid droplets that have departed from the wafer W from re-attaching to the wafer. Therefore, it is preferable that the gas be released from the gas nozzle 43A so as not to be opposite to the flow of the cleaning gas.

[0120] That is, the direction of the release of the gas (the direction of the arrow G) and the angle a (also referred to as "first gas release angle a") formed by the radius direction of the wafer W and the release port of the gas nozzle 43A (refer to arrow F) are preferably 0 ± 90 degrees. Also, from the viewpoint of not being opposite to the flow of the cleaning gas, the direction of the release of the gas (the direction of the arrow G) and the angle β (also referred to as "second gas release angle β") formed by the surface of the wafer W and the release port of the gas nozzle 43A are preferably within the range of 0 to 45 degrees. Figure 8A Figure 8A Figure 8B

[0121] In the above-described first mode, the gas released from the gas nozzle 43A serves to control the liquid departure angle so as to be difficult to attach to the wafer and to suppress the re-attachment of the liquid droplets that have departed by blowing to the wafer.

[0122] The suitable values of the first gas release angle a, the second gas release angle β, and the release speed of the gas (specifically, for example, the release speed at the release port of the gas nozzle 43A) for achieving the above-described various effects can be determined, for example, by experiments in accordance with the state of the chemical liquid (for example, viscosity, surface tension, and the like), the state of the wafer W (for example, the surface state of the hydrophobicity), and the like. The first gas release angle a and the second gas release angle β can be adjusted using the orientation control function of the gas nozzle 43A possessed by the gas nozzle drive mechanism 43B. Also, the release speed of the gas can be adjusted using the flow control means possessed by the gas supply mechanism 43C.

[0123] On the basis of the adjustment of the first gas release angle a, the second gas release angle β, and the release speed of the gas, the first liquid incidence angle θ, the second liquid incidence angle φ, and the release speed of the chemical liquid are adjusted, whereby it is possible to more reliably prevent or suppress the re-attachment of the liquid droplets to the wafer.

[0124] ​​​The processing parameters (e.g., the position of the PE, the position of the PF, the number of rotations of the wafer, the liquid-releasing flow rate, the liquid-releasing flow volume, the gas-releasing flow rate, the gas-releasing flow volume, etc.) including the above-described parameters (α, β, θ, φ) are stored in the storage section of the control device 4 as the processing parameters defined in the processing recipe. The control device 4 controls the devices / equipment such as the processing fluid supply section 40 and the rotational drive section 32 based on the processing recipe to execute the above-described first mode. This is also the same in the following second, third, and fourth modes.

[0125] <Second Mode>

[0126] Next, the second mode will be described with reference to Figure 9A , Figure 9B .

[0127] In the second mode, the gas nozzle 43A is arranged so as to satisfy the following conditions. The gas released from the gas nozzle 43A blows against the landing point PF (PFi) of the liquid. Thereby, the liquid immediately after the detachment from the wafer W or the liquid immediately after the detachment is blown away and immediately moves away from the wafer W.

[0128] At this time, the gas is released from the gas nozzle 43A so that the first liquid detachment angle θS (θSm) is as close to 90 degrees (θSi→θSm) as possible (detachment condition 1) and the second liquid detachment angle φSm (φSm) is as small as possible (φi→φm) as shown in Figure 9A Figure 9B .

[0129] As described in relation to the first mode, by making the direction of the liquid detachment close to the radial direction of the wafer W (i.e., making |90deg-θS| close to zero deg), thereby, the liquid droplet immediately after the detachment from the wafer W moves away from the area near the periphery WE of the wafer W in a short time. In addition, by making the second liquid detachment angle φSm small, the liquid droplet immediately after the detachment from the wafer W moves away from the area near the periphery WE of the wafer W in a short time, and the floating height of the liquid droplet is made low. Therefore, it is possible to reduce the reattachment of the liquid droplet immediately after the detachment to the wafer W.

[0130] According to either of the above-described detachment conditions 1 and 2, it is possible to reduce the possibility of the reattachment of the liquid droplet immediately after the detachment to the wafer W. It does not matter which one of the above-described detachment conditions 1 and 2 is satisfied alone, but it is preferable to satisfy both.

[0131] In addition, according to the second mode, it is possible to prevent or suppress the generation of the liquid droplet flying as a liquid droplet in the area inside the radial direction from the circle including the landing point PF as shown by the arrow VSa. Even if the liquid traveling in the direction shown by the arrow VSa is generated, it is possible to blow it away to the outside of the radial direction of the wafer W using the gas released from the gas nozzle 43A. ​

[0132] Further, at the instant when the chemical liquid lands on the landing point PF, the chemical liquid spreads in the direction along the surface of the wafer W (particularly, the rotational direction of the wafer W). The instant detachment occurs in the area where the chemical liquid spreads. The maximum width of the area where the chemical liquid spreads is larger than the diameter of the liquid column of the chemical liquid released from the release port of the chemical liquid nozzle 41A, for example, 5 mm or so. Therefore, it is preferable to blow the gas so as to sufficiently cover the area where the chemical liquid spreads. In order to achieve the above, the release port of the gas nozzle 43A is preferably a shape in which the lateral direction is longer, such as a rectangular shape, an oblong shape, or the like. The longer length in the lateral direction of the release port of the gas nozzle 43A can be, for example, 10 mm or so. The wind speed of the gas can be, for example, 5 to 30 m / sec or so.

[0133] As with the first mode, in this second mode, appropriate values of the first gas release angle a, the second gas release angle β, and the release speed of the gas can be found through experiments. By adjusting the first liquid incidence angle θ, the second liquid incidence angle φ, and the release speed of the chemical liquid on the basis of adjusting the first gas release angle a, the second gas release angle β, and the release speed of the gas, it is possible to more reliably prevent or inhibit the reattachment of the detached liquid droplets to the wafer.

[0134] <Third Mode>

[0135] Next, the third mode will be described with reference to Figure 10A Figure 10B The third mode is different from the second mode in that an additional nozzle (additional gas nozzle) 43A2 disposed outside the wafer W periphery blows the liquid droplets detached instantaneously from the wafer W downward (see arrow VSm2) to fall on an area lower than the surface of the wafer W. The floating liquid is moved to a height lower than the surface of the wafer W, whereby it is possible to greatly reduce the possibility of the detached liquid droplets reattaching to the surface of the wafer W.

[0136] The additional nozzle 43A2 can be configured so as to enable the gas G2 released from the additional nozzle 43A2 to act on the area (around the arrow VSm) in which the liquid droplets of the chemical liquid detached instantaneously from the wafer W are distributed. It can be that the gas is released straight downward from the additional nozzle 43A2, but it can also be that the additional nozzle 43A2 is slightly inclined so that the gas released from the additional nozzle 43A2 has a velocity component toward the radial direction outside.

[0137] <Fourth Mode>

[0138] Next, the fourth mode will be described. The fourth mode is different from the second mode in that the gas released from the gas nozzle 43A is heated gas. In the fourth mode, the effect of moving the liquid detached instantaneously from the wafer W away from the wafer W is the same as in the second mode.

[0139] ​In the fourth mode, the temperature of the vicinity of the wafer W is raised by the high-temperature (for example, 70 to 150°C, and about 90°C as a specific example) gas released from the gas nozzle 43A (omitted in Figure 11 ). In Figure 11 , the region that becomes high-temperature is indicated by reference numeral H. The minute liquid droplets Lm (indicated by arrow VSa in Figure 8A , Figure 9A , etc.) among the liquid droplets that have separated from the wafer W, and that have scattered in the region inside the radius direction from the circle including the landing point, are vaporized by gasification when passing through the high-temperature region H. Therefore, it is possible to prevent the minute liquid droplets Lm from floating above the wafer W and then falling onto the surface of the wafer W as particles.

[0140] This fourth mode is particularly effective in a liquid medicine of low-boiling-point components such as DHF including fluoric acid, and SC1 including ammonia.

[0141] In parallel with this fourth mode, by heating the wafer W, the temperature of the layer of the heated gas present in the vicinity of the surface of the wafer W is raised, and it is possible to more reliably cause the minute liquid droplets of the liquid medicine to disappear. As a device for heating the wafer W, for example, as indicated by a dashed line in Figure 2 , a heater 44 that is disposed in close proximity to the peripheral portion of the back surface (lower surface) of the wafer W can be used. Alternatively, a nozzle 45 or the like that supplies a heated fluid such as nitrogen gas or HOT DIW (heated pure water) to the peripheral portion of the back surface of the wafer W can be used as a device for heating the wafer W. Such a fluid can be used to prevent the processing liquid (liquid medicine or the like) supplied to the surface of the wafer from returning to the back surface of the wafer, or by heating the wafer W, it can be used to achieve a sufficient reaction speed of the liquid medicine and the wafer.

[0142] Figure 13 is a graph indicating the results of an experiment investigating the relationship between the heater temperature and the number of particles in the case where the heater 44 is provided as described above. From this graph, it is known that by raising the temperature in the vicinity of the surface of the wafer W, it is possible to reduce the number of particles based on the principle described above.

[0143] The embodiments of the present disclosure are illustrative in all aspects and should not be considered as limiting. The above-described embodiments can be omitted, replaced, changed in various ways without departing from the scope recited in the claims and the spirit thereof.

[0144] The substrate to be processed is not limited to a semiconductor wafer, and can be a glass substrate, a ceramic substrate, or the like, and various substrates used in the field of manufacturing semiconductor devices.

Claims

1. A substrate processing apparatus characterized by comprising: including: a substrate holding section capable of holding a substrate; a rotation drive section that rotates the substrate holding section around a rotation axis; a processing liquid nozzle that discharges a processing liquid toward a peripheral edge section of the substrate; and a gas nozzle that discharges a gas toward the processing liquid during a period from a time when the processing liquid is discharged from a discharge port of the processing liquid nozzle to a time when a landing point on the substrate is reached, the discharge port of the gas nozzle has an opening toward a flight trajectory of the processing liquid from the discharge port of the processing liquid nozzle to the landing point on the substrate, in a case where a circle is defined with a center at a foot of a perpendicular line drawn from the landing point to the rotation axis, with a radius of a line segment that connects the foot of the perpendicular line and the landing point, and on a plane orthogonal to the rotation axis, when a straight line that connects a foot of a perpendicular line drawn from the discharge port of the processing liquid nozzle to a surface of the substrate and the landing point forms an angle with a tangent of the circle at the landing point, the angle is an angle θ, the processing liquid nozzle is configured so that the angle θ becomes a first angle smaller than 90 degrees when the gas nozzle does not discharge the gas, the gas nozzle is configured so that the processing liquid discharged from the processing liquid nozzle is turned so that the angle θ becomes a second angle closer to 90 degrees than the first angle when the gas nozzle discharges the gas.

2. The substrate processing apparatus according to claim 1, wherein: when viewed from a direction of the rotation axis, the discharge port of the gas nozzle is disposed closer to a center of the substrate than the discharge port of the processing liquid nozzle.

3. The substrate processing apparatus according to claim 1, wherein: when a straight line that connects a foot of a perpendicular line drawn from the discharge port of the processing liquid nozzle to a surface of the substrate and the landing point forms an angle with a straight line that connects the discharge port of the processing liquid nozzle and the landing point, the angle is an angle φ, the processing liquid nozzle is configured so that the angle φ becomes a first angle smaller than 90 degrees when the gas nozzle does not discharge the gas, the gas nozzle is configured so that the processing liquid discharged from the processing liquid nozzle is turned so that the angle φ becomes a second angle closer to 0 degrees than the first angle when the gas nozzle discharges the gas.

4. A substrate processing apparatus characterized by comprising: including: a substrate holding section capable of holding a substrate; a rotation drive section that rotates the substrate holding section around a rotation axis; a processing liquid nozzle that discharges a processing liquid toward a peripheral edge section of the substrate; and a gas nozzle that discharges a gas toward the processing liquid during a period from a time when the processing liquid is discharged from a discharge port of the processing liquid nozzle to a time when a landing point on the substrate is reached, the discharge port of the gas nozzle has an opening toward the landing point on the substrate of the processing liquid discharged from the processing liquid nozzle, in a case where a circle is defined with a center at a foot of a perpendicular line drawn from the landing point to the rotation axis, with a radius of a line segment that connects the foot of the perpendicular line and the landing point, and on a plane orthogonal to the rotation axis, an angle θS when, as viewed in the direction of the axis of rotation of the substrate, a vector indicating the direction in which the main body of the processing liquid deviates from the landing point toward the outside of the substrate forms an angle with a tangent to the circle at the landing point, the processing liquid nozzle is configured to cause the angle θS to be a first angle smaller than 90 degrees when the gas nozzle is not releasing the gas, the gas nozzle is configured to turn the processing liquid deviating from the landing point so that the angle θS becomes a second angle closer to 90 degrees than the first angle when the gas nozzle is releasing the gas.

5. The substrate processing apparatus according to claim 4, wherein: the release port of the gas nozzle has a slit shape that is longer in the lateral direction.

6. The substrate processing apparatus according to any one of claims 1 to 5, wherein: the gas is a heated gas.

7. The substrate processing apparatus according to any one of claims 1 to 5, further comprising a gas nozzle orientation adjustment mechanism that changes the orientation of the gas nozzle.

8. The substrate processing apparatus according to claim 7, wherein: the gas nozzle orientation adjustment mechanism is capable of adjusting at least any one of: an incident angle of the gas with respect to the surface of the substrate; and an angle formed by a direction in which the gas is released from the gas nozzle and a radial direction of the substrate, as viewed in the direction of the axis of rotation of the substrate.

9. The substrate processing apparatus according to claim 7, further comprising a control section, the control section controls so that the following steps are performed: a step of releasing the processing liquid from the processing liquid nozzle toward the substrate; a step of adjusting the orientation of the gas nozzle with the gas nozzle orientation adjustment mechanism; and a step of releasing the gas from the gas nozzle whose orientation has been adjusted toward the processing liquid flying between the release port of the processing liquid nozzle and the landing point of the processing liquid.

10. The substrate processing apparatus according to claim 7, further comprising a control section, the control section controls so that the following steps are performed: a step of releasing the processing liquid from the processing liquid nozzle toward the substrate; a step of adjusting the orientation of the gas nozzle with the gas nozzle orientation adjustment mechanism; and a step of releasing the gas from the gas nozzle whose orientation has been adjusted toward the landing point of the processing liquid released from the processing liquid nozzle. including: a step of rotating a substrate around an axis of rotation; a step of releasing a processing liquid from a processing liquid nozzle toward a peripheral portion of the rotating substrate; and a step of releasing a gas from a gas nozzle toward the processing liquid during a period from a time when the processing liquid is released from a release port of the processing liquid nozzle to a time when a landing point on the substrate is reached, in the step of releasing the gas, the processing liquid released from the release port of the processing liquid nozzle is blown with the gas to turn the processing liquid before the processing liquid lands on the landing point on the substrate, 11. A method of processing a substrate, characterized by, ​ ​ ​ ​ ​ ​ when a straight line connecting a foot of a perpendicular drawn to a surface of the substrate from a release port of a processing liquid nozzle and the landing point forms an angle of an angle φ with a straight line connecting the release port of the processing liquid nozzle and the landing point, the processing liquid nozzle releases the processing liquid in such a manner that the angle θ becomes a first angle smaller than 90 degrees when the gas nozzle does not release the gas, the gas nozzle releases the gas to turn the processing liquid so that the angle θ becomes a second angle closer to 90 degrees than the first angle.

12. The substrate processing method according to claim 11, wherein: when a straight line connecting a foot of a perpendicular drawn to a surface of the substrate from a release port of a processing liquid nozzle and the landing point forms an angle of an angle φ with a straight line connecting the release port of the processing liquid nozzle and the landing point, the processing liquid nozzle releases the processing liquid in such a manner that the angle φ becomes a first angle smaller than 90 degrees when the gas nozzle does not release the gas, the gas nozzle releases the gas to turn the processing liquid so that the angle φ becomes a second angle closer to 0 degrees than the first angle. including:

13. A method of processing a substrate, characterized by, a step of rotating the substrate around a rotation axis; a step of releasing a processing liquid from a processing liquid nozzle toward a peripheral portion of the rotating substrate; and a step of releasing a gas from a gas nozzle toward the processing liquid during a period from a time when the processing liquid is released from a release port of the processing liquid nozzle to a time when a landing point on the substrate is reached, in the step of releasing the gas, the gas is blown against the landing point on the substrate of the processing liquid released from the release port of the processing liquid nozzle, when a circle is defined with a center at a foot of a perpendicular drawn to the rotation axis from the landing point, with a radius of a line segment connecting the foot of the perpendicular and the landing point, and located in a plane orthogonal to the rotation axis, when a vector indicating a direction in which a main body of the processing liquid deviates from the landing point toward the outside of the substrate forms an angle of an angle θS with a tangent line at the landing point of the circle, the processing liquid nozzle releases the processing liquid in such a manner that the angle θS becomes a first angle smaller than 90 degrees when the gas nozzle does not release the gas, the gas nozzle releases the gas to turn the processing liquid deviated from the landing point so that the angle θS becomes a second angle closer to 90 degrees than the first angle. ​

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