Substrate processing apparatus

1. A substrate processing apparatus comprising:

a chamber, including a base plate having an upper surface that defines a lower side of a housing space;

a substrate holding unit that is housed in the housing space of the chamber, is placed on the upper surface of the base plate, and holds a substrate;

a circular cylindrical guard that surrounds the substrate held by the substrate holding unit and is arranged for being elevated and lowered inside the housing space of the chamber; and

a guard elevation/lowering driving unit that elevates and lowers the guard between an upper position at which an inner peripheral surface of the guard faces a peripheral end surface of the substrate held by the substrate holding unit, and a lower position at which an entirety of the guard is positioned lower than the substrate held by the substrate holding unit,

wherein the guard elevation/lowering driving unit includes a driving source disposed higher than a lower surface of the base plate, and an elevating/lowering head that is connected to the guard and is moved vertically by the driving source within a movable range in which an entirety of the elevating/lowering head is positioned higher than the lower surface of the base plate,

an entirety of the driving source is disposed at a side of the movable range of the elevating/lowering head,

the elevating/lowering head is disposed at a side of the guard, and

the driving source includes a driving motor that is located directly below the guard at a position higher than the lower surface of the base such that a portion of the driving source is located outward from the guard in a radial direction of the guard.

2. The substrate processing apparatus according to claim 1 , wherein the driving source is housed inside the housing space of the chamber.

3. The substrate processing apparatus according to claim 1 , wherein the driving source further includes a rotating shaft that is rotated by the driving motor and extends horizontally, and

the guard elevation/lowering driving unit includes a rotation transmitting unit that transmits the rotation of the rotating shaft to the elevating/lowering head to move the elevating/lowering head vertically.

4. The substrate processing apparatus according to claim 3 , wherein the rotation transmitting unit includes a plurality of rack teeth, fixed to the elevating/lowering head and aligned vertically, and pinion teeth, which are engaged with the rack teeth and to which the rotation of the rotating shaft is transmitted.

5. The substrate processing apparatus according to claim 1 , wherein the driving source further includes a rotating shaft that is rotated by the driving motor and extends vertically, and

the guard elevation/lowering driving unit includes a rotation transmitting unit that transmits the rotation of the rotating shaft to the elevating/lowering head to move the elevating/lowering head vertically.

6. The substrate processing apparatus according to claim 5 , wherein the rotation transmitting unit includes a vertically extending thread shaft, to which the rotation of the rotating shaft is transmitted, and a nut, fixed to the elevating/lowering head and screwed onto the thread shaft.

7. The substrate processing apparatus according to claim 1 , wherein the guard elevation/lowering driving unit includes a guiding unit that guides the vertical movement of the elevating/lowering head.

8. The substrate processing apparatus according to claim 7 , wherein the guiding unit includes a guide member, fixed to the chamber and recess-projection engaged slidably with the elevating/lowering head.

9. The substrate processing apparatus according to claim 1 , further comprising: an isolating member that isolates the guard elevation/lowering driving unit from an atmosphere inside the housing space inside the chamber.

10. The substrate processing apparatus according to claim 1 , further comprising: a fluid supplying nozzle that supplies a fluid to the substrate held by the substrate holding unit; and

a nozzle arm that moves the fluid supplying nozzle horizontally,

wherein the guard elevation/lowering driving unit is disposed directly below a horizontal movement range of the nozzle arm.

11. The substrate processing apparatus according to claim 1 , wherein the elevating/lowering head moves linearly in a vertical direction, and the driving source drives the linear movement of the elevating/lowering head in the vertical direction.

12. The substrate processing apparatus according to claim 1 , wherein the guard includes a first guard, and a second guard that surrounds the first guard,

the elevating/lowering head includes a first guard elevating/lowering head and a second guard elevating/lowering head that are connected to the first guard and the second guard, respectively, and

the driving source includes a first driving source and a second driving source that are located along a circumferential direction of the guard so as to be adjacent to each other, and move the first guard elevating/lowering head and the second guard vertically, respectively.

13. The substrate processing apparatus according to claim 1 , wherein the driving source includes a rotating shaft that is rotated by the driving motor and extends horizontally from the driving motor radially outward,

the elevating/lowering head is located outward from the guard in the radial direction, and

the guard elevation/lowering driving unit includes a rotation transmitting unit that transmits the rotation of the rotating shaft to the elevating/lowering head to move the elevating/lowering head vertically.

14. The substrate processing apparatus according to claim 9 , wherein the isolating member includes a housing that is located directly below the guard and houses an entirety of the driving source and a lower portion of the elevating/lowering head, and a bellows that houses a portion of the elevating/lowering head protruding upward from the housing, and expands and contracts in accordance with the vertical movement of the elevating/lowering head.

15. A substrate processing apparatus comprising:

a chamber which includes a base plate having an upper surface that defines a lower side of a housing space;

a substrate holding unit that is housed in the housing space of the chamber, is placed on the upper surface of the base plate, and holds a substrate;

a shielding plate that faces an upper surface of the substrate held by the substrate holding unit and is elevated and lowered inside the housing space of the chamber;

a shielding plate elevation/lowering driving unit which drives the elevation and lowering of the shielding plate;

a coiled wiring that is connected to the shielding plate, is extensible and contractible vertically, and defines a cylindrical space extending vertically; and

a shaft shaped wiring guide that is elevated and lowered together with the shielding plate, is inserted to the cylindrical space, and guides the extension and contraction of the wiring,

wherein the shielding plate elevation/lowering driving unit includes a driving source that is disposed higher than a lower surface of the base plate, an elevating/lowering head that is connected to the shielding plate and is moved vertically by the driving source within a movable range in which an entirety of the elevating/lowering head is positioned higher than the lower surface of the base plate, and a rotation transmitting unit that transmits the rotation of the rotating shaft to the elevating/lowering head to move the elevating/lowering head vertically,

the driving source includes a driving motor which is disposed higher than a lower surface of the base plate, and a rotating shaft which is rotated by the driving motor and extends vertically,

the rotation transmitting unit includes a vertically extending thread shaft to which the rotation of the rotating shaft is transmitted, and a nut which is fixed to the elevating/lowering head and screwed onto the thread shaft, and

the wiring guide extends in parallel to the thread shaft.

16. The substrate processing apparatus according to claim 15 , further comprising: an isolating member that isolates the shielding plate elevation/lowering driving unit from an atmosphere inside the housing space of the chamber,

wherein the isolating member includes a bellows that is extensible and contractible vertically and houses the wiring and the wiring guide.