Charged particle beam irradiation apparatus

1. A charged particle beam irradiation apparatus comprising:

a charged particle source which emits charged particles;

a sample stub for mounting a sample which is irradiated with the charged particles emitted from the charged particle source thereon;

a driving mechanism including a transmission mechanism which transmits a driving force to move the sample stub;

a vacuum chamber maintaining atmosphere where the sample is placed in a vacuum state; and

a container disposed in the vacuum chamber and accommodating an ionic liquid,

wherein the container is arranged at such a position that at least a part of the transmission mechanism is submerged in the ionic liquid.

2. The charged particle beam irradiation apparatus according to claim 1 , further comprising:

a temperature controlling mechanism controlling the temperature inside the container.

3. The charged particle beam irradiation apparatus according to claim 1 , wherein

the transmission mechanism includes a second mechanical element disposed in the direction that the gravitational field is directed with respect to a power source or a first mechanical element to which a driving force is transmitted from the power source, a driving force being transmitted to the second mechanical element from the first mechanical element; and

the second mechanical element is submerged in the ionic liquid.

4. The charged particle beam apparatus according to claim 1 , wherein

the driving mechanism includes a rotating mechanism that rotates the sample, and

at least a gear included in the rotating mechanism is submerged in the ionic liquid.

5. The charged particle beam apparatus according to claim 1 , wherein

the driving mechanism includes a tilting mechanism that tilts the sample, and

a portion tilted by the tilting mechanism is submerged in the ionic liquid.

6. The charged particle beam apparatus according to claim 5 , wherein

the rotating mechanism that rotates the sample is arranged on the portion tilted by the tilting mechanism, and

at least a part of the rotating mechanism is submerged in the ionic liquid.

7. The charged particle beam irradiation apparatus according to claim 1 , further comprising:

a temperature controlling mechanism that controls the temperature inside the container,

wherein the temperature controlling apparatus maintains the ionic liquid at a predetermined temperature.

8. The charged particle beam irradiation apparatus according to claim 1 , wherein

the charged particle beam irradiation apparatus is an ion milling apparatus.

9. A charged particle beam irradiation apparatus comprising:

a charged particle source which emits charged particles;

a sample stub for mounting a sample which is irradiated with the charged particles emitted from the charged particle source thereon;

a driving mechanism including a transmission mechanism which transmits a driving force to move the sample stub;

a vacuum chamber maintaining atmosphere where the sample is placed in a vacuum state; and

a container disposed in the vacuum chamber and capable of accommodating an ionic liquid,

wherein the driving mechanism includes a first mechanical element to which a driving force is transmitted from a driving source for driving the sample stub, a second mechanical element to which a driving force is transmitted from the first mechanical element and which is positioned in the direction that the gravitational field is directed with respect to the first mechanical element, and a third mechanical element positioned between the second mechanical element and the sample stub, and

the container is positioned so that the second mechanical element is submerged in the ionic liquid.

10. The charged particle beam irradiation apparatus according to claim 9 , further comprising:

a temperature controlling mechanism controls the temperature inside the container.

11. The charged particle beam irradiation apparatus according to claim 10 , further comprising:

a temperature gage that detects the temperature inside the container, wherein

the temperature controlling mechanism controls the temperature of the ionic liquid based on the temperature detected by the temperature gage.

12. A charged particle beam irradiation apparatus comprising:

a charged particle source which emits charged particles;

a sample stub for mounting a sample which is irradiated with the charged particles;

a mechanical element which transmits a driving force from a power source to the sample stub; and

a vacuum chamber where the sample stab and the mechanical element are placed;

wherein a container accommodating an ionic liquid is disposed in the vacuum chamber, and at least a part of the mechanical element is in a state of submerging in the ionic liquid.

13. The charged particle beam irradiation apparatus according to claim 12 , wherein the machine element in the state of submerging in the ionic liquid is a gear, rack, pinion, gear, sprocket, shaft of gear, spur gear, universal ball joint, bevel gear, or ball screw.

14. The charged particle beam irradiation apparatus according to claim 12 , wherein the mechanical element in the state of submerging in the ionic liquid is a gear included in the rotating mechanism that rotates the sample.

15. The charged particle beam irradiation apparatus according to claim 12 , further comprising a temperature controlling mechanism that controls a temperature of the ionic liquid.

16. The charged particle beam irradiation apparatus according to claim 13 , further comprising a temperature controlling mechanism that controls a temperature of the ionic liquid.

17. The charged particle beam irradiation apparatus according to claim 14 , further comprising a temperature controlling mechanism that controls a temperature of the ionic liquid.