阅读说明：本技术 液处理装置和液处理方法 (Liquid processing apparatus and liquid processing method ) 是由 冈泽智树 西山雄太 飞松武志 于 2020-04-17 设计创作，主要内容包括：本发明提供一种液处理装置和液处理方法,对于利用从喷嘴喷出的处理液进行的液处理的面内均匀性有效。液处理装置具备：处理液供给部,其具有喷出处理液的喷嘴；喷嘴移动部,其使所述喷嘴在用于朝向基板的表面供给所述处理液的涂布位置和与所述涂布位置不同的待机位置之间移动；清洗部,其朝向所述待机位置供给清洗液,以通过所述清洗液对位于所述待机位置的所述喷嘴的顶端面进行清洗；吸引部,其具有朝向位于所述待机位置的所述喷嘴的顶端面开口的吸引口,所述吸引部吸引从位于所述待机位置的所述喷嘴喷出的所述处理液以及通过所述清洗部供给到所述待机位置的所述清洗液；以及控制装置,其控制所述处理液供给部、所述喷嘴移动部、所述吸引部及所述清洗部。(The invention provides a liquid treatment apparatus and a liquid treatment method, which are effective for the in-plane uniformity of liquid treatment by using a treatment liquid ejected from a nozzle. The liquid treatment device is provided with: a treatment liquid supply unit having a nozzle for ejecting a treatment liquid; a nozzle moving unit that moves the nozzle between an application position for supplying the processing liquid to a surface of a substrate and a standby position different from the application position; a cleaning unit configured to supply a cleaning liquid toward the standby position to clean a tip end surface of the nozzle located at the standby position with the cleaning liquid; a suction unit having a suction port opening toward a distal end surface of the nozzle located at the standby position, the suction unit sucking the processing liquid discharged from the nozzle located at the standby position and the cleaning liquid supplied to the standby position by the cleaning unit; and a control device for controlling the processing liquid supply unit, the nozzle moving unit, the suction unit, and the cleaning unit.)

1. A liquid treatment apparatus is characterized by comprising:

a treatment liquid supply unit having a nozzle for ejecting a treatment liquid;

a nozzle moving unit that moves the nozzle between an application position for supplying the processing liquid to a surface of a substrate and a standby position different from the application position;

a cleaning unit configured to supply a cleaning liquid toward the standby position to clean a tip end surface of the nozzle located at the standby position with the cleaning liquid;

a suction unit having a suction port opening toward a distal end surface of the nozzle located at the standby position, the suction unit sucking the processing liquid discharged from the nozzle located at the standby position and the cleaning liquid supplied to the standby position by the cleaning unit; and

and a control device for controlling the treatment liquid supply unit, the nozzle moving unit, the suction unit, and the cleaning unit.

2. The liquid treatment apparatus according to claim 1,

the suction unit stops sucking the processing liquid from the suction port after the processing liquid supply unit stops discharging the processing liquid from the nozzle located at the standby position.

3. The liquid treatment apparatus according to claim 1 or 2,

the cleaning part comprises: a cleaning tank disposed at the standby position; and a cleaning liquid supply unit for supplying the cleaning liquid into the cleaning tank,

the suction port is opened towards the inside of the cleaning tank,

the cleaning liquid supply unit supplies the cleaning liquid into the cleaning tank in which the nozzle is housed; and

the suction unit sucks the cleaning liquid supplied into the cleaning tank by the cleaning liquid supply unit.

4. The liquid treatment apparatus according to claim 3,

the suction part is also provided with a suction head which protrudes relative to the bottom wall of the cleaning tank,

the suction port is opened on the upper surface of the suction head.

5. The liquid treatment apparatus according to claim 4,

the cleaning part is also provided with a liquid outlet which is arranged on the bottom wall of the cleaning tank and discharges the cleaning liquid to the outside of the cleaning tank,

the liquid discharge port is located around the suction head.

6. The liquid treatment apparatus according to claim 5,

the suction head protrudes toward the top end face of the nozzle housed in the cleaning tank,

The liquid discharge port is located on a lower surface of a height difference portion formed by the suction head and the bottom wall.

7. The liquid treatment apparatus according to claim 5 or 6,

the plurality of liquid discharge ports are provided at positions where the suction head is sandwiched.

8. The liquid treatment apparatus according to claim 5 or 6,

the liquid discharge port is provided in plural, and the plural liquid discharge ports are formed in a circumferential direction around the suction port.

9. The liquid treatment apparatus according to claim 5 or 6,

the size of the liquid discharge port is larger than that of the suction port.

10. The liquid treatment apparatus according to claim 1 or 2,

the diameter of the suction port is 0.7 to 1.3 times the diameter of the discharge port of the nozzle.

11. The liquid treatment apparatus according to claim 1 or 2,

in a state where the nozzle is located at the standby position, the nozzle and the suction portion are arranged such that a center of an ejection port of the nozzle and a center of the suction port of the suction portion substantially coincide with each other, and the processing liquid ejected from the nozzle approaches each other to such an extent that the processing liquid is sucked by the suction port without spreading to a distal end surface of the nozzle.

12. The liquid treatment apparatus according to claim 1 or 2,

the cleaning unit further includes a gas supply unit that supplies gas toward a lower end portion of the nozzle located at the standby position.

13. A method of treating a liquid, comprising:

moving a nozzle, which is included in a treatment liquid supply unit and discharges a treatment liquid, between an application position for supplying the treatment liquid toward a surface of a substrate and a standby position different from the application position;

causing the treatment liquid supply unit to discharge the treatment liquid from the nozzle in a state where the nozzle is located at the standby position;

a suction unit having a suction port opening toward a distal end surface of the nozzle located at the standby position, the suction unit sucking the processing liquid discharged from the nozzle located at the standby position,

supplying a cleaning liquid toward the standby position by a cleaning section that cleans the tip surface of the nozzle at the standby position with the cleaning liquid to clean the nozzle at the standby position; and

and causing the suction unit to suck the cleaning liquid supplied to the standby position by the cleaning unit.

14. The liquid treatment method according to claim 13,

the standby position is a position where the center of the discharge port of the nozzle and the center of the suction port substantially coincide with each other and the nozzle and the suction portion are close to each other to such an extent that the processing liquid discharged from the nozzle is sucked by the suction port without spreading to the distal end surface of the nozzle.

15. The liquid treatment method according to claim 13 or 14,

after the cleaning liquid is supplied to the nozzle located at the standby position, a gas is supplied toward a lower end of the nozzle in a state where the nozzle is located at the standby position.

Technical Field

The present disclosure relates to a liquid treatment apparatus and a liquid treatment method.

Background

Patent document 1 discloses a liquid treatment apparatus including: a plurality of liquid processing parts, each of which is formed by arranging a substrate holding part for horizontally holding a substrate in the cup body; a treatment liquid nozzle for supplying a treatment liquid to the substrate; and a liquid removing unit that removes droplets of the processing liquid hanging down from the processing liquid nozzle between the openings of the cup body.

Disclosure of Invention

Problems to be solved by the invention

The present disclosure provides a liquid processing apparatus and a liquid processing method effective for in-plane uniformity of liquid processing by a processing liquid ejected from a nozzle.

Means for solving the problems

A liquid treatment apparatus according to one aspect of the present disclosure includes: a treatment liquid supply unit having a nozzle for ejecting a treatment liquid; a nozzle moving unit that moves the nozzle between an application position for supplying the processing liquid to a surface of a substrate and a standby position different from the application position; a cleaning unit configured to supply a cleaning liquid toward the standby position to clean a tip end surface of the nozzle located at the standby position with the cleaning liquid; a suction unit having a suction port opening toward a distal end surface of the nozzle located at the standby position, the suction unit sucking the processing liquid discharged from the nozzle located at the standby position and the cleaning liquid supplied to the standby position by the cleaning unit; and a control device for controlling the processing liquid supply unit, the nozzle moving unit, the suction unit, and the cleaning unit.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present disclosure, a liquid processing apparatus and a liquid processing method effective for in-plane uniformity of liquid processing by a processing liquid discharged from a nozzle are provided.

Drawings

Fig. 1 is a schematic diagram showing an example of a schematic configuration of a liquid processing apparatus.

Fig. 2 is a schematic cross-sectional view showing an example of the cleaning section and the suction section.

Fig. 3 is a schematic diagram showing an example of the structure of the liquid receiving section when viewed from above.

Fig. 4 is a block diagram showing an example of the functional configuration of the control device.

Fig. 5 is a block diagram showing an example of the hardware configuration of the control device.

Fig. 6 is a flowchart showing an example of the liquid processing procedure.

Fig. 7 is a flowchart showing an example of the nozzle cleaning process.

Fig. 8a to 8d are schematic views for explaining a nozzle cleaning method.

Fig. 9 is a flowchart showing an example of the dummy ejection process.

Fig. 10a to 10d are schematic diagrams for explaining the dummy ejection method.

Description of the reference numerals

1: a liquid treatment device; 20: a treatment liquid supply unit; 25: a nozzle; 25 a: an ejection port; 25 b: a top end face; 30: a drive mechanism; 40: a cleaning section; 51: a cleaning tank; 51 b: a bottom wall; 53a, 54 a: a liquid discharge port; 60: a cleaning liquid supply section; 80: a suction part; 81: a suction head; 81 a: a suction port; 81 b: a top end face; 100: a control device; w: a wafer; wa: a surface.

Detailed Description

Hereinafter, an example of an embodiment according to the present disclosure will be described with reference to the drawings. In the following description, the same reference numerals are used for the same elements or elements having the same function, and redundant description is omitted.

[ liquid treatment apparatus ]

The structure of the liquid treatment apparatus 1 will be described with reference to fig. 1 to 3. As shown in fig. 1, the liquid processing apparatus 1 is configured to supply a processing liquid L1 to a surface Wa of a wafer W (substrate). The treatment liquid L1 may be any of various liquids that can be applied to the surface Wa of the wafer W, and may be, for example, a photosensitive etching resist solution that is a photosensitive etching resist film, a non-photosensitive etching resist solution that is a non-photosensitive etching resist film, or a developing solution for developing an etching resist film.

The wafer W may have a circular plate shape or a plate shape other than a circular shape such as a polygonal shape. The wafer W may have a notch portion with a part cut away. The notch may be a notch (a U-shaped or V-shaped groove), or a linear portion (i.e., an orientation flat) extending linearly. The wafer W may be, for example, a semiconductor substrate, a glass substrate, a mask substrate, an FPD (Flat Panel Display) substrate, or other various substrates. The diameter of the wafer W may be, for example, about 200mm to 450 mm.

The liquid processing apparatus 1 includes a substrate holding unit 10, a processing liquid supply unit 20, a drive mechanism 30 (nozzle moving unit), a cleaning unit 40, a suction unit 80, and a control unit 100.

The substrate holding portion 10 includes a rotation holding portion 11 and a cup 12. The rotation holding portion 11 includes a rotation portion 13, a shaft 14, and a holding portion 15. The rotating portion 13 operates based on an operation signal from the control device 100, and rotates the shaft 14. The rotating portion 13 is a power source such as an electric motor. The holding portion 15 is provided at the distal end portion of the shaft 14. The wafer W can be placed on the holding portion 15. The holding unit 15 is, for example, a suction chuck configured to hold the wafer W substantially horizontally by suction or the like.

That is, the rotation holding portion 11 has a function of rotating the wafer W about an axis (rotation axis) perpendicular to the front surface Wa of the wafer W in a state where the posture of the wafer W is substantially horizontal. In the present embodiment, the rotation axis passes through the center of the circular wafer W, and therefore is also the center axis.

The cup 12 is provided around the rotation holding portion 11. The cup 12 functions as a liquid collecting container for receiving the liquid supplied to the wafer W for processing the wafer W. The cup 12 may be made of polypropylene (PP), polyvinyl chloride (PVC), polyphenylene Sulfide (PPS), or the like.

The processing liquid supply unit 20 is configured to supply the processing liquid L1 to the front surface Wa of the wafer W. The processing liquid supply unit 20 includes a liquid source 21, a pump 22, a valve 23, a pipe 24, and a nozzle 25.

The liquid source 21 functions as a supply source of the processing liquid L1. The pump 22 operates based on an operation signal from the control device 100, sucks the treatment liquid L1 from the liquid source 21, and sends the treatment liquid L1 to the nozzle 25 via the pipe 24 and the valve 23. The valve 23 operates based on an operation signal from the control device 100 to connect or disconnect the pipes 24 in front of and behind the valve 23. The liquid source 21, the pump 22, the valve 23, and the nozzle 25 are connected to the pipe 24 in this order from the upstream side.

The nozzle 25 is configured to discharge the treatment liquid L1. Specifically, the nozzle 25 has a function of discharging the processing liquid L1 sent from the pump 22 downward from the discharge port 25a (see fig. 2). The discharge port 25a is provided on a tip surface 25b of the nozzle 25. The tip end surface 25b is, for example, a lower end surface located at a lower end of the nozzle 25. The tip face 25b may be flat. For example, the top end face 25b may be horizontal. Further, the distal end surface 25b may be inclined with respect to the horizontal direction. The tip end face 25b may be partially cut away. The discharge port 25a may be circular or polygonal as viewed in the vertical direction (downward). The nozzle 25 is provided with a flow path connected to the discharge port 25 a. The flow path within the nozzle 25 may have a substantially fixed diameter. Alternatively, the diameter of the flow path in the nozzle 25 may be increased in the vicinity of the discharge port 25 a.

The drive mechanism 30 operates based on an operation signal from the control device 100 to move the nozzle 25 in the horizontal direction or the vertical direction. The driving mechanism 30 may be, for example, a servo motor with an encoder to control the moving speed and the moving position of the nozzle 25. The drive mechanism 30 moves the nozzle 25 between an application position for supplying the processing liquid L1 toward the front surface Wa of the wafer W and a standby position different from the application position.

The application position is a position at which the processing liquid L1 discharged from the discharge port 25a of the nozzle 25 can be attached to the surface Wa of the wafer W. For example, the application position is an arbitrary portion within an area defined by the outer edge of the cup 12 when viewed from above. Alternatively, the application position is an arbitrary portion in a region defined by the outer edge of the wafer W held by the holding portion 15 when viewed from above. The standby position is a position for preparation (maintenance of the nozzle 25) for supplying the processing liquid L1 toward the front surface Wa of the wafer W. For example, the standby position is an arbitrary portion outside the region defined by the outer edge of the wafer W when viewed from above. Alternatively, the standby position is an arbitrary portion outside the area defined by the outer edge of cup 12 when viewed from above. In the present specification, the discharge of the treatment liquid L1 from the nozzle 25 located at the application position toward the front surface Wa of the wafer W is referred to as "true discharge". The discharge of the processing liquid L1 from the nozzle 25 located at the standby position to a place different from the wafer W for the preparation of the true discharge is referred to as "dummy discharge". The driving mechanism 30 may move the nozzle 25 between the center of the wafer W and the outer edge of the wafer W during the vacuum ejection.

The cleaning unit 40 is configured to clean the distal end surface 25b of the nozzle 25 at the standby position with the cleaning liquid L2. The cleaning unit 40 includes a liquid receiving unit 50 and a cleaning liquid supply unit 60.

The liquid receiver 50 functions as a liquid collecting container for receiving the processing liquid L1 and the cleaning liquid L2 during the dummy discharge. As shown in fig. 1 and 2, the liquid receiving section 50 includes a cleaning tank 51 and a nozzle 52. The cleaning tank 51 is disposed at a standby position. As described above, when the standby position is outside the region defined by the outer edge of cup 12, cleaning tub 51 is disposed outside cup 12. The cleaning tank 51 is a bottomed cylindrical case with an upper portion opened. As shown in fig. 2 and 3, the cleaning tank 51 has a side wall 51a and a bottom wall 51 b.

The nozzle 52 is provided on the side wall 51a of the cleaning tank 51, and is configured to discharge the cleaning liquid L2 into the cleaning tank 51. The nozzle 52 may be configured to generate a swirling flow in the cleaning tank 51 by the discharged cleaning liquid L2. For example, the opening direction of the discharge port of the nozzle 52 (the discharge direction of the cleaning liquid L2 from the nozzle 52) may extend in the circumferential direction around the substantial center of the bottom wall 51b when viewed in the vertical direction.

The cleaning liquid supply unit 60 is configured to supply a cleaning liquid L2 into the cleaning tank 51. The cleaning liquid L2 may be various organic solvents (e.g., a diluent). The cleaning liquid supply unit 60 includes a liquid source 61, a pump 62, a valve 63, and a pipe 64.

The liquid source 61 functions as a supply source of the cleaning liquid L2. The pump 62 operates based on an operation signal from the control device 100, sucks the cleaning liquid L2 from the liquid source 61, and sends the cleaning liquid L2 to the nozzle 52 via the pipe 64 and the valve 63. The valve 63 operates based on an operation signal from the control device 100, and connects or disconnects the pipes 64 in front of and behind the valve 63. The liquid source 61, the pump 62, the valve 63, and the nozzle 52 are connected to the pipe 64 in this order from the upstream side.

The cleaning unit 40 may further include a gas supply unit 70. The gas supply unit 70 is configured to supply gas toward the lower end of the nozzle 25. The gas G may be any of various inert gases, such as nitrogen (N)₂Gas). The gas supply unit 70 includes a gas source 71, a pump 72, a valve 73, a pipe 74, and a nozzle 75.

The gas source 71 functions as a supply source of the gas G. The pump 72 operates based on an operation signal from the control device 100, sucks the gas G from the gas source 71, and sends the gas G to the nozzle 75 through the pipe 74 and the valve 73. The valve 73 operates based on an operation signal from the control device 100, and connects or disconnects the pipes 64 before and after the valve 73.

A gas source 71, a pump 72, a valve 73, and a nozzle 75 are connected to the pipe 74 in this order from the upstream side. The nozzle 75 is fixed in the cleaning tank 51 so that a discharge port at the tip thereof is directed obliquely downward. The nozzle 75 has a function of ejecting the gas G sent from the gas source 71 obliquely downward from the ejection port. In the example shown in fig. 1, the gas supply unit 70 supplies gas into the cleaning tank 51, but the gas supply unit 70 may be configured to supply gas into a tank different from the cleaning tank 51. In this case, the nozzle 75 may eject the gas toward the nozzle 25 located in the different tank.

The suction unit 80 is configured to suck the processing liquid L1 and the cleaning liquid L2. The suction unit 80 includes a suction head 81 and a suction device 82. The suction head 81 is a rod-shaped body extending in the vertical direction. The suction head 81 may be formed in a cylindrical shape or a polygonal columnar shape, for example. A suction port 81a for sucking the processing liquid L1 or the cleaning liquid L2 is provided in a distal end surface 81b (upper surface) of the suction head 81. The suction port 81a opens toward the distal end surface 25b of the nozzle 25 located at the standby position. In this example, the distal end surface 81b of the suction head 81 faces the distal end surface 25b of the nozzle 25 located at the standby position, and the suction port 81a opens toward the distal end surface 25 b. The tip face 81b may be flat. The distal end surface 81b may be horizontal or inclined with respect to the horizontal direction. A flow path connected to the suction port 81a is provided in the suction head 81. The flow path extends in the vertical direction. The flow path may have a substantially fixed diameter. The diameter of the flow path in the suction head 81 may be increased near the suction port 81 a.

As shown in fig. 2, suction head 81 is provided such that suction port 81a is located in cleaning tank 51. As shown in fig. 3, the suction tip 81 may be disposed such that the suction port 81a is located at substantially the center of the bottom wall 51b when viewed from above. Suction head 81 may protrude upward with respect to the inner surface of bottom wall 51b of cleaning tank 51. That is, the height position of the tip surface 81b of the suction head 81 may be higher than the inner surface of the bottom wall 51 b. The suction head 81 may be fixed to the cleaning tank 51. For example, suction head 81 may be fixed to bottom wall 51b of cleaning tank 51 in a state of penetrating bottom wall 51b in the vertical direction. Further, suction head 81 may not protrude from bottom wall 51b of cleaning tank 51. For example, the distal end surface 81b of the suction head 81 may be located at substantially the same height as the bottom wall 51 b. Suction head 81 may be fixed to side wall 51a without being fixed to bottom wall 51b of cleaning tank 51. The suction tip 81 may be provided at a position away from the side wall 51a and the bottom wall 51 b. In this case, the suction head 81 may be fixed to the cleaning tank 51 via a fixing member.

The suction port 81a may be circular or polygonal as viewed in the vertical direction (upward). The size (area) of the suction port 81a may be substantially equal to the size of the discharge port 25a of the nozzle 25, may be smaller than the size of the discharge port 25a, or may be larger than the size of the discharge port 25a, as viewed in the vertical direction. For example, the diameter of the suction port 81a may be 0.7 to 1.3 times the diameter of the discharge port 25 a. Alternatively, the diameter of the suction port 81a may be 0.75 to 1.25 times the diameter of the discharge port 25 a. In the case where both the suction port 81a and the discharge port 25a are circular, the diameter of the suction port 81a may be 0.7 to 1.3 times or 0.75 to 1.25 times the diameter of the discharge port 25 a.

The suction device 82 is connected to the lower end of the suction head 81. The suction device 82 is a pump that performs a suction operation to suck the treatment liquid L1 or the cleaning liquid L2 through the suction port 81 a. The suction device 82 performs a suction operation in response to an operation signal from the control device 100.

The liquid receiving unit 50 may further include liquid discharge units 53 and 54 (see fig. 2). The liquid discharging units 53 and 54 are configured to discharge the processing liquid L1 and the cleaning liquid L2 supplied into the cleaning tank 51. The liquid discharge portions 53, 54 may be provided on the bottom wall 51 b. The liquid discharge portions 53 and 54 have liquid discharge ports 53a and 54a opened in the cleaning tank 51 and liquid discharge pipes 53b and 54b extending downward from the bottom wall 51 b. The storage space inside the cleaning tank 51 is connected to a space outside the cleaning tank 51 (for example, inside the liquid discharge tank) via liquid discharge ports 53a and 54a and flow paths inside liquid discharge pipes 53b and 54 b. Thus, the cleaning liquid L2 in the cleaning tank 51 is discharged to the outside of the cleaning tank 51 through the liquid discharge ports 53a and 54 a.

The liquid discharge ports 53a and 54a are provided around the suction port 81a located at the substantially center of the bottom wall 51 b. For example, as shown in fig. 3, the liquid discharge ports 53a and 54a are arranged with the suction port 81a interposed between the liquid discharge port 53a and the liquid discharge port 54a when viewed from above. The liquid discharge ports 53a and 54a may be formed to extend in the circumferential direction around the substantial center of the bottom wall 51 b. The size (area) of the liquid discharge port 53a and the size (area) of the liquid discharge port 54a may be smaller than the size of the suction port 81a, respectively, when viewed in the vertical direction. Further, a single drain port may be provided in the bottom wall 51b of the cleaning tank 51, or 3 or more drain ports may be provided. The size of the liquid discharge port provided in the bottom wall 51b may be substantially the same as the size of the suction port 81a, or may be smaller than the size of the suction port 81 a. Further, the bottom wall 51b may not be provided with a drain port, and the cleaning liquid L2 in the cleaning tank 51 may be discharged by the suction unit 80.

The control device 100 controls each element included in the liquid treatment apparatus 1. The control device 100 is configured to execute the following control: causing the treatment liquid supply unit 20 to discharge the treatment liquid L1 from the nozzle 25 in a state where the nozzle 25 is positioned at the standby position; a suction unit 80 for sucking the treatment liquid L1 discharged from the nozzle 25 located at the standby position; supplying a cleaning liquid L2 to the cleaning unit 40 toward the standby position to clean the nozzle 25 located at the standby position; the suction unit 80 is caused to suck the cleaning liquid L2 supplied to the standby position by the cleaning unit 40.

As shown in fig. 4, the control device 100 includes a dummy discharge control unit 101, a vacuum discharge control unit 102, a cleaning liquid supply control unit 103, a first suction control unit 104, a second suction control unit 105, a nozzle movement control unit 106, a gas supply control unit 107, and a rotation control unit 108 as functional blocks.

The dummy discharge control unit 101 has a function of controlling the treatment liquid supply unit 20 to discharge the treatment liquid L1 from the nozzle 25 at the standby position. Specifically, when the nozzle 25 is located at the standby position (in the cleaning tank 51), the dummy ejection control section 101 controls the pump 22 and the valve 23 of the treatment liquid supply section 20 to eject (dummy ejection) the treatment liquid L1 from the nozzle 25 toward the suction port 81a of the suction head 81.

The vacuum ejection control section 102 has a function of controlling the processing liquid supply section 20 to eject the processing liquid L1 from the nozzle 25 at the supply position. Specifically, when the nozzle 25 is located at the supply position, the vacuum ejection control unit 102 controls the pump 22 and the valve 23 of the processing liquid supply unit 20 to cause the nozzle 25 to eject (vacuum-eject) the processing liquid L1 toward the surface Wa of the wafer W.

The cleaning liquid supply control unit 103 has a function of controlling the cleaning liquid supply unit 60 to supply the cleaning liquid L2 from the nozzle 52 to the standby position. Specifically, in a state where the nozzle 25 is housed in the cleaning tank 51, the cleaning liquid supply control unit 103 controls the pump 62 and the valve 63 of the cleaning liquid supply unit 60 to supply the cleaning liquid L2 into the cleaning tank 51. The cleaning liquid supply control section 103 supplies the cleaning liquid L2 into the cleaning tank 51 through the cleaning liquid supply section 60 to such an extent that the distal end face 25b of the nozzle 25 is submerged in the cleaning tank 51 by the cleaning liquid L2.

The first suction control unit 104 has a function of controlling the suction unit 80 to suck the processing liquid L1 discharged from the nozzle 25 located at the standby position. Specifically, when the dummy discharge is performed from the nozzle 25, the first suction control unit 104 controls the suction device 82 to cause the suction unit 80 to suck the processing liquid L1 discharged from the nozzle 25. In this case, the processing liquid L1 that is pseudo-discharged from the nozzle 25 is sucked through the suction port 81a and the flow path in the suction head 81 connected to the suction port 81 a.

The second suction control unit 105 has a function of controlling the suction unit 80 to suck the cleaning liquid L2 supplied into the cleaning tank 51. Specifically, when the cleaning liquid L2 is supplied into the cleaning tank 51, the second suction control unit 105 controls the suction device 82 to cause the suction unit 80 to suck the cleaning liquid L2 in the cleaning tank 51. In this case, the cleaning liquid L2 supplied into the cleaning tank 51 is sucked from the suction port 81a through the flow path in the suction head 81 and discharged to the outside of the cleaning tank 51.

The nozzle movement control unit 106 has a function of controlling the driving mechanism 30 to move the nozzle 25 between the supply position and the standby position. For example, after the nozzle 25 performs the dummy ejection and before the nozzle 25 performs the real ejection, the nozzle movement control unit 106 moves the nozzle 25 from the standby position to the supply position by the driving mechanism 30. After the vacuum discharge from the nozzle 2 is performed and before the cleaning of the nozzle 25 is performed, the nozzle movement control unit 106 moves the nozzle 25 from the supply position to the standby position by the drive mechanism 30. When the nozzle 25 performs the vacuum ejection, the nozzle movement control unit 106 may move the nozzle 25 in a direction along the front surface Wa of the wafer W by the driving mechanism 30. For example, the nozzle movement control unit 106 may move the nozzle 25 between the center axis of the wafer W and the outer edge of the wafer W while performing the vacuum ejection from the nozzle 25 to the surface Wa of the rotating wafer W by the drive mechanism 30.

The gas supply controller 107 has a function of controlling the gas supply unit 70 to eject the gas G from the nozzle 75 toward the distal end surface 25b of the nozzle 25. Specifically, when the nozzle 25 is located at the standby position (in the cleaning tank 51), the gas supply control unit 107 controls the pump 72 and the valve 73 of the gas supply unit 70 to discharge the gas G from the nozzle 75 toward the distal end surface 25b of the nozzle 25. Thus, when the deposit adheres to the distal end surface 25b of the nozzle 25, the gas G is ejected to the deposit.

The rotation control unit 108 has a function of controlling the rotation unit 13 to rotate the wafer W held by the holding unit 15 at a predetermined rotation speed. For example, while the vacuum ejection control unit 102 performs the vacuum ejection from the nozzles 25, the rotation control unit 108 may drive the rotating unit 13 to rotate the wafer W.

The control device 100 is constituted by one or more control computers. For example, the control device 100 has a circuit 120 shown in fig. 5. The circuit 120 has one or more processors 121, memory 122, storage 123, input-output ports 124, and timers 125. The storage device 123 is, for example, a hard disk or the like, and has a storage medium readable by a computer. The storage medium stores a program for causing the control device 100 to execute a liquid processing procedure described later. The storage medium may be a removable medium such as a nonvolatile semiconductor memory, a magnetic disk, and an optical disk. The memory 122 temporarily stores a program loaded from a storage medium of the storage device 123 and an operation result of the processor 121. The processor 121 and the memory 122 execute the programs in cooperation with each other, thereby configuring the functional blocks described above. The input/output port 124 inputs and outputs an electric signal between the input/output port 124 and a member to be controlled in accordance with an instruction from the processor 121. The timer 125 measures the elapsed time by, for example, counting a fixed period of reference pulses.

The hardware configuration of the control device 100 is not necessarily limited to the configuration of each functional block by a program. For example, each functional block of the control device 100 may be formed of a dedicated logic Circuit or an ASIC (application specific Integrated Circuit) into which the logic Circuit is Integrated.

[ liquid treatment Process ]

Next, a liquid processing process performed in the liquid processing apparatus 1 will be described as an example of the liquid processing method with reference to fig. 6 to 10.

As shown in fig. 6, in the liquid processing procedure, first, the control device 100 executes step S01. In step S01, the controller 100 controls the elements of the liquid treatment apparatus 1 to supply the treatment liquid L1 to the front surface Wa of the wafer W. Specifically, in step S01, the nozzle movement control unit 106 first controls the drive mechanism 30 to move the nozzle 25 and dispose the nozzle 25 at the supply position. Then, the vacuum ejection control unit 102 controls the processing liquid supply unit 20 (the pump 22 and the valve 23) to eject (vacuum-eject) the processing liquid L1 from the nozzle 25 toward the front surface Wa of the wafer W. At this time, the rotation control unit 108 controls the rotation unit 13 to rotate the wafer W supported by the holding unit 15 at a predetermined rotation speed. Thereby, the processing liquid L1 is applied to the surface Wa of the wafer W.

Next, the control device 100 executes steps S02 and S03. In step S02, the control device 100 controls the drive mechanism 30, the cleaning unit 40, and the suction unit 80 to clean the nozzle 25. Details of the cleaning process in step S02 will be described later. In step S03, the control device 100 controls the treatment liquid supply unit 20, the drive mechanism 30, and the suction unit 80 to spurt the treatment liquid L1 from the nozzle 25 and to suck the spurted treatment liquid L1 from the suction port 81 a. Details of the dummy ejection process in step S03 will be described later. Control device 100 repeats the processing of steps S01 to S03.

When the application of the processing liquid L1 is performed in step S01 (after the application is completed), the processing liquid L1 may adhere to the distal end surface 25b of the nozzle 25 (see fig. 8 a). For example, when the processing liquid L1 is discharged toward the front surface Wa in a state where the distal end surface 25b of the nozzle 25 is brought close to the front surface Wa of the wafer W, the processing liquid L1 is likely to adhere to the distal end surface 25 b. Further, "close proximity" refers to a state in which the distal end surface 25b is slightly separated from the surface Wa without being in contact with the surface Wa. The distance between the distal end surface 25b and the surface Wa may be, for example, about 0.01mm to 2.0 mm. The cleaning process in step S02 is performed in order to remove the processing liquid L1 adhering to the tip end face 25 b.

When the nozzle 25 is cleaned in step S02, the cleaning liquid L2 supplied to the lower end portion of the nozzle 25 may slightly enter the nozzle 25 from the discharge port 25 a. After the series of cleaning processes, the cleaning liquid L2 entering the nozzle 25 may remain (see fig. 8 d). In order to discharge the cleaning liquid L2 remaining in the nozzle 25, the dummy ejection process of step S03 is performed at the standby position. After the application of the processing liquid L1 by the nozzle 25 in this manner, the processing liquid L1 is removed from the distal end surface 25b of the nozzle 25 and the cleaning liquid L2 is removed from the nozzle 25 by executing steps S02 and S03, and the application of the processing liquid L1 in step S01 is performed again. By repeatedly performing steps S01 to S03, the dummy ejection process of step S03 is executed before the process of step S01 is performed each time.

(cleaning Process)

As shown in fig. 7, in the cleaning process of step S02, after the surface Wa of the wafer W is coated with the processing liquid L1, the control apparatus 100 executes step S21. In step S21, the nozzle movement control unit 106 controls the drive mechanism 30 to move the nozzle 25 from the supply position to the standby position, thereby placing the nozzle 25 at the standby position. For example, the nozzle movement control unit 106 controls the drive mechanism 30 to store the nozzle 25 in the cleaning tank 51, and to dispose the nozzle 25 in the cleaning tank 51 such that the distal end surface 25b of the nozzle 25 faces the distal end surface 81b of the suction head 81.

Next, the control device 100 executes steps S22 and S23. In step S22, the cleaning liquid supply control unit 103 controls the cleaning liquid supply unit 60 to start discharging the cleaning liquid L2 from the nozzle 52 provided on the side wall 51a of the cleaning tank 51. In step S23, the control device 100 waits until a predetermined first predetermined time elapses. Thereby, as shown in fig. 8b, the cleaning liquid L2 is supplied into the cleaning tank 51. The nozzle 52 continues to supply the cleaning liquid L2 into the cleaning tank 51 until a first predetermined time elapses after the cleaning liquid L2 starts to be discharged from the nozzle 52.

At this time, while the cleaning liquid L2 is supplied into the cleaning tank 51, a part of the cleaning liquid L2 supplied into the cleaning tank 51 is discharged out of the cleaning tank 51 through the liquid discharge ports 53a and 54 a. Therefore, the cleaning liquid supply control unit 103 may continue the supply of the cleaning liquid L2 from the nozzle 52 by the cleaning liquid supply unit 60 so that the liquid level of the cleaning liquid L2 in the cleaning tank 51 is maintained at a position above the distal end surface 25b of the nozzle 25. When the processing liquid L1 adheres to the distal end surface 25b of the nozzle 25 (around the discharge port 25 a) by performing steps S22 and S23, the adhering processing liquid L1 is removed by the cleaning liquid L2 (see fig. 8 b).

Next, the control device 100 executes steps S24 and S25. In step S24, the second suction control unit 105 controls the suction device 82 to suck the cleaning liquid L2 supplied into the cleaning tank 51 from the suction port 81a (via the flow path in the suction head 81). In step S25, the control device 100 waits until a predetermined second predetermined time elapses. Thereby, as shown in fig. 8c, the cleaning liquid L2 is sucked into the suction head 81 from the suction port 81 a. At this time, when the treatment liquid L1 adheres to the inner surface of the flow path in the suction head 81 at the time of dummy discharge, the adhered treatment liquid L1 is removed by the cleaning liquid L2. In this manner, the control device 100 first performs the process of supplying the cleaning liquid L2 from the cleaning unit 40 into the cleaning tank 51 in a state where the suction operation by the suction unit 80 is stopped. Thereafter, the control device 100 executes the following processing: while the cleaning section 40 supplies the cleaning liquid L2 into the cleaning tank 51, the suction section 80 sucks the cleaning liquid L2 in the cleaning tank 51.

Next, control device 100 executes step S26. In step S26, the cleaning liquid supply control unit 103 controls the pump 62 and the valve 63 of the cleaning liquid supply unit 60 to stop the ejection of the cleaning liquid L2 from the nozzle 52. Thereby, the supply of the cleaning liquid L2 from the nozzle 52 into the cleaning tank 51 is stopped. As shown in fig. 8d, the cleaning liquid L2 remaining in the cleaning tank 51 is discharged outside the cleaning tank 51 through the liquid discharge ports 53a and 54a and the suction unit 80 that continues the suction operation.

Next, control device 100 executes step S27. In step S27, the second suction control unit 105 controls the suction device 82 of the suction unit 80 to stop the suction of the cleaning liquid L2 by the suction port 81 a. When the cleaning liquid L2 remains in the cleaning tank 51 after the suction of the cleaning liquid L2 through the suction port 81a is stopped, the remaining cleaning liquid L2 is discharged from the liquid discharge ports 53a and 54a to the outside of the cleaning tank 51.

Next, control device 100 executes step S28. In step S28, the gas supply controller 107 controls the pump 72 and the valve 73 of the gas supply unit 70 to discharge the gas G from the nozzle 75 (see fig. 2) toward the distal end surface 25b of the nozzle 25. In step S27, a small amount of the cleaning liquid L2 may remain on the distal end surface 25 b. In this case, the gas G is supplied to blow off the adhered cleaning liquid L2, thereby removing the cleaning liquid L2 from the distal end surface 25 b. Through the above, the washing process is ended.

In a series of cleaning processes, the control device 100 may cause the suction unit 80 to suck the cleaning liquid L2 during the entire period of time during which the cleaning liquid L2 is supplied into the cleaning tank 51 by the cleaning liquid supply unit 60 (hereinafter referred to as "cleaning liquid supply period"). As in the above-described cleaning process, when the control device 100 causes the suction unit 80 to suck the cleaning liquid L2 supplied into the cleaning tank 51 during a part of the cleaning liquid supply period, the use period of the suction device 82 is reduced, and therefore, the progress of deterioration of the suction device 82 can be suppressed. After the cleaning liquid supply period is ended, the control device 100 may cause the suction unit 80 to suck the cleaning liquid L2 remaining in the cleaning tank 51. If the gas supply unit 70 is not provided in the liquid processing apparatus 1, the ejection of the gas G in step S28 may be omitted.

(false ejection Process)

As shown in fig. 9, in the dummy ejection process in step S03, after the cleaning of the nozzles 25, the control device 100 executes step S31. In step S31, the nozzle movement control unit 106 controls the drive mechanism 30 to move the nozzle 25 so that the ejection port 25a of the nozzle 25 is positioned in the vicinity of the suction port 81a of the suction head 81. In other words, the nozzle movement controller 106 arranges the nozzle 25 at a position near the suction port 81a (see fig. 10 a).

The position near the suction port 81a is a position at which the discharge port 25a and the suction port 81a are close to each other at the standby position to such an extent that the processing liquid L1 discharged from the nozzle 25 can be sucked into the suction port 81a without spreading to the top end surface 25 b. In this case, the nozzle movement control unit 106 may arrange the nozzle 25 at the position near the center of the discharge port 25a and the center of the suction port 81a so as to substantially coincide with each other.

Next, control device 100 executes step S32. In step S32, the first suction control unit 104 controls the suction device 82 of the suction unit 80 so that the suction port 81a can suck the processing liquid L1. That is, the first suction control unit 104 causes the suction unit 80 to start the suction operation.

Next, the control device 100 executes steps S33 and S34. In step S33, the dummy ejection control unit 101 controls the pump 22 and the valve 23 of the treatment liquid supply unit 20 to perform dummy ejection of the treatment liquid L1 from the ejection port 25a of the nozzle 25. In step S34, the control device 100 waits until a predetermined third predetermined time elapses. In step S32, since the suction by the suction unit 80 is started, the treatment liquid L1 that has been temporarily discharged is sucked into the suction port 81a (see fig. 10 b). In this manner, in the state where the nozzle 25 is positioned at the standby position, the control device 100 controls the treatment liquid supply unit 20 and the suction unit 80 so that the treatment liquid L1 is discharged from the nozzle 25 and the treatment liquid L1 discharged from the nozzle 25 is sucked by the suction unit 80. As a result, the cleaning liquid L2 remaining in the nozzle 25 during the cleaning process is discharged from the nozzle 25 while the treatment liquid L1 is temporarily discharged.

Next, control device 100 executes step S35. In step S35, the dummy ejection control unit 101 controls the pump 22 and the valve 23 of the treatment liquid supply unit 20 to stop the dummy ejection of the treatment liquid L1 from the ejection port 25a of the nozzle 25. Thereby, the discharge of the processing liquid L1 from the discharge port 25a is stopped, and the processing liquid L1 remaining in the suction head 81 is sucked and removed (see fig. 10 c).

Next, the control device 100 executes steps S36 and S37. In step S36, the control device 100 waits until a predetermined fourth predetermined time elapses. In step S37, the first suction control unit 104 controls the suction device 82 so that the processing liquid L1 cannot be sucked from the suction port 81 a. That is, the first suction control unit 104 stops the suction operation performed by the suction unit 80.

Thus, the suction of the suction port 81a is continued until the fourth predetermined time elapses after the discharge of the treatment liquid L1 is stopped in step S35. During this time, the processing liquid L1 remaining in the nozzle 25 is sucked into the suction port 81a, and therefore the processing liquid L1 in the nozzle 25 rises (also referred to as "suck-back") as shown in fig. 10 d. That is, the lowest height position of the treatment liquid L1 in the nozzle 25 rises. By adjusting the fourth predetermined time, the amount of the treatment liquid L1 that rises in the nozzle 25 fluctuates between the time when the discharge of the treatment liquid L1 from the nozzle 25 is stopped and the time when the suction operation by the suction port 81a is stopped. With this, the dummy ejection sequence ends.

In a series of dummy ejection processes, the control device 100 may stop the ejection of the treatment liquid L1 from the nozzle 25 and the suction operation by the suction unit 80 at substantially the same timing. In step S12 of the cleaning process performed before the dummy ejection process, the nozzle 25 may be arranged at the position near the nozzle to perform a series of cleaning processes. In this case, the process of step S31 may be omitted in the dummy ejection process.

[ Effect of the embodiment ]

The liquid treatment apparatus 1 according to the present embodiment described above includes: a treatment liquid supply unit 20 having a nozzle 25 for discharging a treatment liquid L1; a drive mechanism 30 that moves the nozzle 25 between an application position for supplying the processing liquid L1 toward the front surface Wa of the wafer W and a standby position different from the application position; a suction unit 80 having a suction port 81a opening toward the distal end surface 25b of the nozzle 25 located at the standby position; a cleaning unit 40 for cleaning the distal end surface 25b of the nozzle 25 at the standby position with a cleaning liquid L2; and a control device 100 for controlling the treatment liquid supply unit 20, the drive mechanism 30, the suction unit 80, and the cleaning unit 40. The control device 100 executes the following control: causing the treatment liquid supply unit 20 to discharge the treatment liquid L1 from the nozzle 25 in a state where the nozzle 25 is positioned at the standby position; a suction unit 80 for sucking the treatment liquid L1 discharged from the nozzle 25 located at the standby position; supplying a cleaning liquid L2 to the cleaning unit 40 toward the standby position to clean the nozzle 25 located at the standby position; and a suction unit 80 for sucking the cleaning liquid L2 supplied to the standby position by the cleaning unit 40.

The liquid treatment method according to the present embodiment includes: moving a nozzle 25, which is provided in the processing liquid supply unit 20 and discharges the processing liquid L1, between an application position for supplying the processing liquid L1 toward the front surface Wa of the wafer W and a standby position different from the application position; causing the treatment liquid supply unit 20 to discharge the treatment liquid L1 from the nozzle 25 in a state where the nozzle 25 is positioned at the standby position; a suction unit 80 for sucking the processing liquid L1 discharged from the nozzle 25 located at the standby position, the suction unit 80 having a suction port 81a opening toward the distal end surface 25b of the nozzle 25 located at the standby position; supplying a cleaning liquid L2 to the standby position by a cleaning liquid L2 in a cleaning section 40 for cleaning the distal end surface 25b of the nozzle 25 at the standby position, to clean the nozzle 25 at the standby position; and a suction unit 80 for sucking the cleaning liquid L2 supplied to the standby position by the cleaning unit 40.

In the liquid processing apparatus 1 and the liquid processing method, the suction unit is caused to suck the processing liquid L1 and to spurt the processing liquid L1 from the nozzle 25 in a state where the nozzle 25 is positioned at the standby position. When the treatment liquid L1 is discharged from the nozzle 25 in a pseudo manner, the discharged treatment liquid L1 may adhere to the distal end surface 25b of the nozzle 25, but the treatment liquid L1 is less likely to adhere to the distal end surface 25b by sucking the treatment liquid L1 by the suction portion 80. Therefore, the adhesion of the processing liquid L1 to the distal end surface 25b of the nozzle 25 due to the false discharge from the nozzle 25 can be suppressed. When the processing liquid L1 adheres to the distal end surface 25b due to the dummy discharge, the supply amount of the processing liquid L1 increases at the time point when the discharge of the processing liquid L1 from the nozzle 25 toward the wafer W starts. In this case, although variations in the processing performed by the processing liquid L1 occur within the surface of the wafer W, in the above configuration, since the adhesion of the processing liquid L1 to the tip surface 25b can be suppressed, the in-plane uniformity of the liquid processed by the processing liquid L1 within the wafer W can be improved.

When the distal end surface 25b of the nozzle 25 is cleaned with the cleaning liquid L2, the cleaning liquid L2 used for cleaning is sucked by the suction portion 80, and therefore the processing liquid L1 sucked and remaining in the suction portion 80 at the time of dummy discharge is removed. Therefore, the suction effect of the suction unit 80 can be continued. In this manner, the liquid processing apparatus 1 and the liquid processing method described above are effective for the in-plane uniformity of the liquid processed wafer W by the processing liquid L1 discharged from the nozzle 25.

In the above embodiment, the control device 100 further performs the following control: after the treatment liquid supply unit 20 stops discharging the treatment liquid L1 from the nozzle 25 located at the standby position, the suction unit 80 stops sucking the treatment liquid L1 from the suction port 81 a. In this case, since the suction of the suction port 81a is continued even after the discharge of the processing liquid L1 from the nozzle 25 is stopped, the processing liquid L1 in the nozzle 25 rises as compared with the case after the discharge of the processing liquid L1 is stopped. For example, by adjusting the time for continuing the suction of the suction unit 80 after the stop of the discharge of the processing liquid L1, the position (the lowermost height position) of the processing liquid L1 in the nozzle 25 can be adjusted.

In the above embodiment, the cleaning unit 40 includes: a cleaning tank 51 disposed at a standby position; and a cleaning liquid supply unit 60 for supplying a cleaning liquid L2 into the cleaning tank 51. Suction port 81a opens into cleaning tank 51. The control device 100 executes the following control: in a state where the nozzle 25 is housed in the cleaning tank 51, the cleaning liquid supply section 60 supplies the cleaning liquid L2 into the cleaning tank 51; the suction unit 80 is caused to suck the cleaning liquid L2 supplied from the cleaning liquid supply unit 60 into the cleaning tank 51. In this case, in a state where the nozzle 25 is housed in the cleaning tank 51, the cleaning liquid L2 is supplied into the cleaning tank 51, and the cleaning liquid L2 is stored in the cleaning tank 51. Therefore, since the tip end surface 25b of the nozzle 25 continues to be immersed in the cleaning liquid L2, the processing liquid L1 adhering to the tip end surface 25b is more reliably removed. Further, by sucking the cleaning liquid L2 stored in the cleaning tank 51 by the suction unit 80, the cleaning liquid L2 can be efficiently sent to the suction port 81 a.

In the above embodiment, suction unit 80 further includes suction head 81 protruding from bottom wall 51b of cleaning tank 51. The suction port 81a opens on the upper surface of the suction head 81. After the nozzle 25 is cleaned, the cleaning liquid L2 may remain on the bottom wall 51b in the cleaning tank 51. In this case, the cleaning liquid L2 after cleaning the nozzle 25 may adhere to the distal end surface 25b of the nozzle 25 via the suction port 81 a. In the above configuration, since the suction head 81 protrudes from the bottom wall 51b, the cleaning liquid L2 after cleaning the nozzle 25 is less likely to adhere to the suction port 81 a. Therefore, contamination of the distal end surface 25b of the nozzle 25 by the cleaning liquid L2 after cleaning the nozzle 25 can be suppressed.

The cleaning section 40 further has drain ports 53a and 54a provided in the bottom wall 51b of the cleaning tank 51 for discharging the cleaning liquid L2 to the outside of the cleaning tank 51. The liquid discharge ports 53a and 54a are located around the suction head 81. Since the suction head 81 protrudes from the bottom wall 51b, the cleaning liquid L2 is likely to remain in the step portion formed by the periphery of the tip end surface 81b of the suction head 81 and the bottom wall 51b even if the suction portion 80 performs suction. In the above configuration, since the cleaning liquid L2 remaining in the stepped portion is discharged through the liquid discharge ports 53a and 54a, accumulation of the cleaning liquid L2 can be prevented in the bottom wall 51b (stepped portion). Therefore, contamination of the distal end surface 25b of the nozzle 25 due to accumulation of the cleaning liquid L2 can be prevented.

The size of the liquid discharge ports 53a and 54a is larger than the suction port 81 a. In this case, the cleaning liquid L2 after cleaning the nozzle 25 can be discharged from the liquid discharge ports 53a and 54a as soon as possible.

The diameter of the suction port 81a is 0.7 to 1.3 times the diameter of the discharge port 25a of the nozzle 25. When the diameter of the suction port 81a is too small relative to the diameter of the discharge port 25a, a part of the processing liquid L1 discharged from the discharge port 25a may not be sucked by the suction portion 80, and a part of the processing liquid L1 that is not sucked may spread toward the tip surface 25b around the discharge port 25 a. On the other hand, if the diameter of the suction port 81a is too large relative to the diameter of the discharge port 25a, the liquid column of the processing liquid L1 formed during suction may expand to substantially the same extent as the diameter of the suction port 81a between the discharge port 25a and the suction port 81 a. The liquid column expands (the cross section of the liquid column increases), and the processing liquid may adhere to the distal surface 25b around the ejection port 25a due to the liquid column. In the above configuration, since the diameter of the suction port 81a is not too small or too large relative to the diameter of the discharge port 25a, the treatment liquid L1 can be prevented from adhering to the tip surface 25b around the discharge port 25a during the dummy discharge.

The embodiments have been described above, but the present disclosure is not limited to the above embodiments, and various modifications can be made without departing from the scope of the present disclosure.