Focused ion beam apparatus
View Patent ↗In order to implement faster high precision milling and high resolution image observation in the structure analysis and failure analysis of the MEMS and semiconductor devices, a two-lens optical system is mounted on a focused ion beam apparatus, and in the optical system the distance from an emitter apex in an ion source to an earth electrode included in a condenser lens and disposed nearest to the ion source is in the range of 5 to 14 mm.
1. A focused ion beam apparatus including an ion source, a condenser lens and an objective lens to accelerate an ion beam emitted from the ion source and focus the ion beam onto a specimen, a deflector to scan the specimen with the focused ion beam, and a beam limiting aperture to limit a beam current or a beam diameter of the focused ion beam, wherein:
the condenser lens comprises at least a first electrode supplied with an extraction voltage, and a second electrode supplied with an earth potential,
a distance from an emitter apex of the ion source to the second electrode included in the condenser lens is in the range of 5 to 14 mm, and
a distance from the emitter apex of the ion source to the condenser lens center is 45 mm or less.
2. The focused ion beam apparatus according to claim 1 , wherein the ion source is a liquid metal ion source.
3. The focused ion beam apparatus according to claim 1 , wherein a voltage applied to the emitter in the ion source is in a range of 29 to 41 kV.
4. The focused ion beam apparatus according to claim 1 , wherein an optical length from the emitter apex in the ion source to the specimen is in a range of 300 to 450 mm.
5. A focused ion beam apparatus including an ion source, a condenser lens and an objective lens to accelerate an ion beam emitted from the ion source and focus the ion beam onto a specimen, a deflector to scan the specimen with the focused ion beam, and a beam limiting aperture to limit a beam current or a beam diameter of the focused ion beam, wherein:
a focused ion beam is formed, in which a beam current I p is at least 20 nA, and a beam diameter d in a specimen position does not exceed 3 μm and the beam diameter d in the specimen position is 0.5 (I p /20 nA) 3/2 μm or less, and
a distance from an emitter apex of the ion source to the condenser lens center is 45 mm or less.
6. The focused ion beam apparatus according to claim 5 , wherein an optical length from the emitter apex in the ion source to the specimen is in a range of 300 to 450 mm.
7. A focused ion beam apparatus including an ion source, a condenser lens and an objective lens to accelerate an ion beam emitted from the ion source and focus the ion beam onto a specimen, a deflector to scan the specimen with the focused ion beam, and a beam limiting aperture to limit a beam current or a beam diameter of the focused ion beam, wherein:
the condenser lens comprises at least a first electrode supplied with an extraction voltage, and a second electrode supplied with an earth potential,
a distance from an ion emitter apex of the ion source to the second electrode included in the condenser lens is in the range of 5 to 14 mm, and
a distance from the ion emitter apex to a third electrode for dominantly performing lens action of the condenser lens is 45 mm or less.