Placement apparatus and processing apparatus

1. A placement apparatus, the apparatus comprising:

a stage on which a substrate is placed;

a support configured to support the stage from a side of a rear surface of the stage that is opposite to a placement surface on which the substrate is placed;

a temperature adjustment member including a plate securing the stage from a lower surface of the stage, a shaft extending downwards from the plate, and a hole accommodating the support through the shaft from the plate, and being capable of a temperature adjustment;

a heat-insulating member disposed between the stage and the temperature adjustment member; and

an annular member configured to abut the substrate placed on the stage,

wherein the stage further includes:

a gas flow path having at least one opening for ejecting a gas;

a placement recess in which the substrate is received and placed; and

at least one dug-down portion formed at a radially outer side than the placement recess to communicate with the placement recess, and

wherein the gas ejected from the opening passes through a space formed between a side surface of the substrate and a side surface of the at least one dug-down portion, and the gas flows radially outwards in a space between the stage and the annular member,

wherein the gas flow path has a first flow path formed between the rear surface of the stage and an upper surface of the heat-insulating member, and a second flow path one end of which communicates with the first flow path and the other end of which communicates with the at least one opening,

wherein the second flow path has a third flow path formed from the rear surface of the stage, and a fourth flow path one end of which communicates with the third flow path and the other end of which communicates with the at least one opening, and

wherein a flow path cross-sectional area of the fourth flow path is smaller than a flow path cross-sectional area of the third flow path.

2. The placement apparatus of claim 1 , wherein the at least one opening of the gas flow path is formed in a bottom surface of the at least one dug-down portion, and

wherein the at least one dug-down portion includes a plurality of dug-down portions provided and disposed at regular intervals.

3. The placement apparatus of claim 1 , wherein the at least one opening of the gas flow path has a circular shape, and

wherein a circular shape of the placement recess and the circular shape of the at least one opening are in contact with each other when the stage is viewed in a plan view.

4. The placement apparatus of claim 2 , wherein the at least one opening of the gas flow path has a circular shape, and

wherein a circular shape of the placement recess and the circular shape of the at least one opening are in contact with each other when the stage is viewed in a plan view.

5. The placement apparatus of claim 1 , wherein the at least one dug-down portion has a diameter that is equal to or larger than a diameter of the fourth flow path, and is equal to or smaller than a diameter of the third flow path.

6. The placement apparatus of claim 5 , wherein the at least one opening of the gas flow path is provided at a position at a more upstream side of an abutment portion of the substrate and the annular member.

7. The placement apparatus of claim 6 , wherein the stage has a heater inside to heat the substrate, and

wherein the heater has a size equal to or larger than a diameter of an inner peripheral surface of the annular member when the annular member abuts the substrate.

8. The placement apparatus of claim 7 , wherein the gas is a purge gas that pushes out a processing gas from the space between the stage and the annular member, the processing gas flows from the abutment portion between the substrate and the annular member into the space between the stage and the annular member.

9. The placement apparatus of claim 1 , wherein the at least one opening of the gas flow path is provided at a position at a more upstream side of an abutment portion between the substrate and the annular member.

10. The placement apparatus of claim 1 , wherein the stage has a heater inside to heat the substrate, and

wherein the heater has a size equal to or larger than a diameter of an inner peripheral surface of the annular member when the annular member abuts the substrate.

11. The placement apparatus of claim 1 , wherein the gas is a purge gas that pushes out a processing gas from the space between the stage and the annular member, the processing gas flows from an abutment portion between the substrate and the annular member into the space between the stage and the annular member.

12. A processing apparatus, the processing apparatus comprising the placement apparatus according to claim 1 .