Ion implantation apparatus and method of cleaning ion implantation apparatus

1. An ion implantation apparatus in which a fluorine compound gas is used as a source gas of an ion source, comprising:

a vacuum chamber into which the source gas is introduced;

an introduction passage connected to the vacuum chamber and configured to introduce into the vacuum chamber a cleaning gas containing a component that reacts with a fluorine compound deposited inside the vacuum chamber and generates a reactant gas;

a delivery device connected to the introduction passage and configured to forcibly introduce the cleaning gas into the introduction passage;

a first valve inserted into the introduction passage and configured to adjust an amount of gas flow in the introduction passage;

an exhausting passage connected to the vacuum chamber and configured to forcibly exhaust the reactant gas from the vacuum chamber along with the cleaning gas;

a second valve inserted into the exhausting passage and configured to adjust an amount of gas flow in the exhausting passage; and

a controller configured to control the amount of gas flow by the first and second valves and to control a pressure in the vacuum chamber, in accordance with an operation of the delivery device, wherein

the cleaning gas is an ambient air including moisture, and

the delivery device includes at least one of a positive pressure pump or a fan configured to pressurize the cleaning gas to an atmospheric pressure or higher and to deliver the compressed cleaning gas to the introduction passage.

2. The ion implantation apparatus according to claim 1 , wherein

the controller controls the first valve while the delivery device is in operation so as to introduce the cleaning gas into the vacuum chamber, and controls the second valve to exhaust the reactant gas and the cleaning gas from the vacuum chamber.

3. The ion implantation apparatus according to claim 2 , wherein

the controller controls the pressure in the vacuum chamber by detecting the pressure in the vacuum chamber while the delivery device is in operation.

4. The ion implantation apparatus according to claim 2 , wherein

the controller controls the pressure in the vacuum chamber by detecting the pressure in the vacuum chamber containing the cleaning gas and reactant gas, while the amount of gas flow in the introduction passage adjusted by the first valve is larger than the amount of gas flow in the exhausting passage adjusted by the second valve.

5. The ion implantation apparatus according to claim 2 , wherein

the controller controls the first valve and the second valve so that the pressure in the vacuum chamber is constant.

6. The ion implantation apparatus according to claim 5 , wherein

the pressure in the vacuum chamber is below 1.0 atm.

7. The ion implantation apparatus according to claim 2 , wherein

the delivery device introduces the cleaning gas at a pressure between 1.0 atm and 5 atm.

8. The ion implantation apparatus according to claim 2 , wherein

the controller controls at least one of the first and second valves so that the pressure (P) in the vacuum chamber remains in a range 0.1 atm≤P<1.0 atm while the delivery device is in operation.

9. The ion implantation apparatus according to claim 2 , wherein

the controller controls at least one of the first and second valves so that the pressure (P) in the vacuum chamber remains in a range 0.1 atm≤P<1.5 atm while the delivery device is in operation.

10. The ion implantation apparatus according to claim 1 , wherein

the vacuum chamber is provided with an opening at the connection to the introduction passage, and with a diffusing member for diffusing the cleaning gas introduced via the opening toward a wall surface of the vacuum chamber.

11. The ion implantation apparatus according to claim 1 , wherein

the exhausting passage is provided with an exhaust device for forcibly exhausting the reactant gas.

12. The ion implantation apparatus according to claim 11 , wherein

the exhaust device is provided with a dry pump resistant to corrosion.

13. The ion implantation apparatus according to claim 1 , wherein

denoting the conductance of the introduction passage by C 1 , and the conductance of the exhausting passage by C 2 , the introduction passage and the exhausting passage are configured such that C 1 <C 2 .

14. The ion implantation apparatus according to claim 1 , wherein

the apparatus is configured to meet S 1 <S 2 , where S 1 denotes a cross sectional area of the introduction passage and S 2 denotes a cross sectional area of the exhausting passage.

15. The ion implantation apparatus according to claim 1 , wherein

the vacuum chamber comprises the arc chamber that is an ion source head, a source housing accommodating the arc chamber, and an ion beamline, and

the arc chamber is connected with the introduction passage, and the source housing or the ion beamline is connected with the exhausting passage.

16. The ion implantation apparatus according to claim 15 , wherein

the introduction passage is provided in the source housing or the ion beamline.

17. The ion implantation apparatus according to claim 15 , wherein

the vacuum chamber forms at least a part of the source housing and the ion beamline.

18. The ion implantation apparatus according to claim 1 , wherein

the exhausting passage is provided with a detection device configured to detect a concentration of the exhausted reactant gas.