Ion milling device, ion source, and ion milling method
To provide an ion gun of a penning discharge type capable of achieving a milling rate which is remarkably higher than that in the related art, an ion milling device including the same, and an ion milling method. An ion generation unit includes a cathode that emits electrons, an anode that is provided within the ion generation unit and has an inner diameter of 5.2 mm or less, and magnetic-field generation means using a permanent magnet of which a maximum energy product ranges from 110 kJ/m 3 to 191 kJ/m 3 .
1. An ion milling device comprising:
an ion source configured to cause electrons to collide with a gas supplied from an outside of the ion milling device and to generate ions; and
an acceleration electrode at which a voltage of 5 kV or more is applied as an electrode that accelerates the ions emitted from the ion source, and that irradiates a sample with the accelerated ions so as to process the sample,
wherein the ion source includes
a cathode from which the electrons are emitted;
an anode that is provided within the ion source and has an inner diameter of 5.2 mm or less; and
a magnetic-field generator that generates a magnetic field within the ion source by using a samarium-cobalt magnet.
2. The ion milling device according to claim 1 ,
wherein the samarium-cobalt magnet has a cylindrical shape.
3. The ion milling device according to claim 1 ,
wherein a voltage of 6 kV or more is applied to the acceleration electrode.
4. The ion milling device according to claim 1 ,
wherein the ion source is a penning type.
5. The ion milling device according to claim 1 ,
wherein a residual magnetic flux density remaining in a permanent magnet of the magnetic-field generator in an absence of a voltage being present at said anode of the ion source ranges from 810 mT to 950 mT.
6. The ion milling device according to claim 1 ,
wherein a holding force of the magnetic-field generator ranges from 620 mT to 660 mT.
7. The ion milling device according to claim 1 ,
wherein a shape of the anode is a cylindrical shape, and an inner diameter of the anode is the same as a diameter of an outlet hole of the anode.
8. The ion milling device according to claim 1 ,
wherein a diameter of an outlet hole of the anode is smaller than an inner diameter of the anode.
9. The ion milling device according to claim 8 ,
wherein the diameter of the outlet hole of the anode is 4 mm.
10. An ion source that is used in an ion milling device that includes the ion source which causes electrons to collide with a gas supplied from an outside of the ion milling device and that generates ions, and an acceleration electrode at which a voltage of 5 kV or more is applied as an electrode that accelerates the ions emitted from the ion source, and that irradiates a sample with the accelerated ions so as to process the sample, the ion source comprising:
a cathode from which the electrons are emitted;
an anode which is provided within the ion source, and has an inner diameter of 5.2 mm or less; and
a magnetic-field generator that generates a magnetic field within the ion source by using a samarium-cobalt magnet.
11. The ion source according to claim 10 ,
wherein the samarium-cobalt magnet has a cylindical shape.
12. The ion source according to claim 10 ,
wherein a voltage of 6 kV or more is applied to the acceleration electrode.
13. The ion source according to claim 10 ,
wherein the ion source is a penning type.
14. The ion source according to claim 10 ,
wherein a residual magnetic flux density of a permanent magnet of the magnetic-field generator in an absence of a voltage being present at said anode of the ion source ranges from 810 mT to 950 mT.
15. The ion source according to claim 10 ,
wherein a holding force of the magnetic-field generator ranges from 620 mT to 660 mT.
16. An ion milling device comprising:
an ion source configured to receive a supplied gas; and
an acceleration electrode at which a voltage of 5 kV or more is applied,
wherein the ion source includes
a cathode;
an anode having an inner diameter of 5.2 mm or less; and
a samarium-cobalt magnet having a cylindrical shape.
17. An ion source that is used in an ion milling device that includes the ion source configured to receive a supplied gas, and an acceleration electrode at which a voltage of 5 kV or more is applied, the ion source comprising:
a cathode;
an anode having an inner diameter of 5.2 mm or less; and
a samarium-cobalt magnet having a cylindrical shape.