Two-fluid nozzle and substrate liquid processing apparatus and substrate liquid processing method

1. A two-fluid nozzle for spraying, toward a processing target object, droplets of a processing solution which are formed by mixing the processing solution discharged from a liquid discharge portion and a gas discharged from a ring-shaped gas discharge opening formed on a lower surface of the two-fluid nozzle,

wherein the liquid discharge portion includes a plurality of spaced liquid discharge openings arranged along a circle inside the ring-shaped gas discharge opening,

the plurality of spaced liquid discharge openings are inclined relative to the lower surface and are fluidly coupled to a liquid inlet opening, each of the plurality of spaced liquid discharge openings being configured to obliquely discharge the processing solution in an outward direction toward the ring-shaped gas discharge opening,

a distance between adjacent liquid discharge openings among the plurality of the liquid discharge openings is set to be a distance allowing processing solutions discharged from the respective liquid discharge openings not to contact each other in a region under the liquid discharge portion until the processing solution discharged from the respective liquid discharge openings collide with the gas,

a distance between each of the liquid discharge openings and the ring-shaped gas discharge opening is set to be a distance allowing processing solutions discharged from adjacent liquid discharge openings to be mixed with the gas while not being contacted with each other,

the ring-shaped gas discharge opening is configured to discharge the gas in a downward direction, and

the liquid discharge openings and the ring-shaped gas discharge opening are positioned on the lower surface of the two-fluid nozzle facing the processing target object, such that the droplets of the processing solution are formed outside of the two-fluid nozzle.

2. The two-fluid nozzle of claim 1 , wherein the distance between the adjacent liquid discharge openings is equal to or larger than a diameter of one of the liquid discharge openings.

3. The two-fluid nozzle of claim 1 ,

wherein the ring-shaped gas discharge opening has a slit shape.

4. The two-fluid nozzle of claim 1 , further comprising:

a vortex flow generating portion configured to generate a vortex of the gas, which is discharged from the ring-shaped gas discharge opening.

5. A substrate liquid processing apparatus for performing a liquid process on a substrate by using droplets of a processing solution, the substrate liquid processing apparatus comprising:

a substrate holding unit configured to rotate the substrate while holding the substrate thereon;

a cup positioned to surround the substrate held on the substrate holding unit to receive the processing solution therein; and

a two-fluid nozzle for discharging the droplets of the processing solution toward the substrate,

wherein the two-fluid nozzle forms the droplets of the processing solution by mixing the processing solution discharged from a liquid discharge portion and a gas discharged from a ring-shaped gas discharge opening formed on a lower surface of the two-fluid nozzle,

the liquid discharge portion includes a plurality of spaced liquid discharge openings arranged along a circle inside the ring-shaped gas discharge opening,

the plurality of spaced liquid discharge openings are inclined relative to the lower surface and are fluidly coupled to a liquid inlet opening, each of the plurality of spaced liquid discharge openings being configured to obliquely discharge the processing solution in an outward direction toward the ring-shaped gas discharge opening,

a distance between adjacent liquid discharge openings among the plurality of the liquid discharge openings is set to be a distance allowing processing solutions discharged from the respective liquid discharge openings not to contact with each other in a region under the liquid discharge portion until the processing solution discharged from the respective liquid discharge openings collide with the gas,

a distance between each of the liquid discharge openings and the ring-shaped gas discharge opening is set to be a distance allowing processing solutions discharged from adjacent liquid discharge openings to be mixed with the gas while not being contacted with each other,

the ring-shaped gas discharge opening is configured to discharge the gas in a downward direction, and

the liquid discharge openings and the ring-shaped gas discharge opening are positioned on the lower surface of the two-fluid nozzle facing the substrate, such that the droplets of the processing solution are formed outside of the two-fluid nozzle.

6. The two-fluid nozzle of claim 5 , wherein the distance between the adjacent liquid discharge openings is equal to or larger than a diameter of one of the liquid discharge openings.

7. The substrate liquid processing apparatus of claim 5 ,

wherein the ring-shaped gas discharge opening has a slit shape.

8. The substrate liquid processing apparatus of claim 5 , further comprising:

a vortex flow generating portion configured to generate a vortex of the gas, which is discharged from the ring-shaped gas discharge opening.

9. A substrate liquid processing method for performing a liquid process on a substrate by spraying, toward a processing target object, droplets of a processing solution which are formed by mixing the processing solution discharged from a liquid discharge portion and a gas discharged from a ring-shaped gas discharge opening,

wherein the liquid process is performed by using a two-fluid nozzle as claimed in claim 1 .