Dual beam system
AssigneeFEI Company
InventorTom Miller
Life of this patent
Estimating the term…
Abstract
A dual beam system provides for operation of a focused ion beam in the presence of a magnetic field from an ultra-high resolution electron lens. The ion beam is deflected to compensate for the presence of the magnetic field.
Claims20
A method of operating a dual beam system, comprising:
- providing an electron column for generating an electron beam and focusing an electron beam onto a sample, the electron column including a magnetic objective lens that produces a magnetic field that extends to the sample surface, the magnetic field having a strength of at least 0.025 Tesla at the sample surface;
- and
- directing a focused ion beam toward the sample surface in the presence of the magnetic field, the displacement by the magnetic field of the ion beam being compensated for and the compensation increasing the spot size of the beam by less than 50%.
A method of operating a focused ion beam column in the presence of a magnetic field from an electron immersion lens, comprising:
- directing a beam of electrons toward a sample, the electrons being focused by a magnetic immersion objective lens having a magnetic field that extends to the sample;
- and
- directing a beam of ions toward a point on the sample surface in the presence of the magnetic field from the electron immersion lens;
- and
- deflecting the beam of ions to compensate for the effect of the magnetic field on the ion beam, the ion beam being directed to process the sample with sub-micron accuracy in the presence of the magnetic field.
A dual beam system for processing and imaging microscopic structures on a sample, comprising:
- an electron beam column, the column including a magnetic immersion lens for producing a magnetic field that extends to the sample;
- an ion beam column, comprising:
- a source of ions;
- an ion electrostatic objective lens;
- a first deflector for compensating for the presence of a magnetic field within the ion column by deflecting the ion beam toward the center of the ion electrostatic objective lens;
- and
- a second deflector for deflecting the ion beam to compensate for the displacement of the ion beam by the magnetic field so that the ion beam impacts the sample at the same position that would be impacted if the immersion lens were not operating.
A dual beam system for processing and imaging microscopic structures on a sample, comprising:
- an electron beam column, the column including a magnetic immersion lens that produces a magnetic field that extends to the sample;
- an ion beam column, comprising:
- an electrostatic objective lens;
- and
- one or more deflectors deflecting the ion beam, the deflectors having applied thereto voltages to compensate for the magnetic field of the immersion lens, such that the spot size of the ion beam is increased by less than 50% by the deflection.
The dual beam system of 18 in which the magnetic immersion lens produces a magnetic at the sample surface of greater than 0.05 Tesla.
The dual beam system of 18 in which a first one of the one or more deflectors compensates for the magnetic field within the ion beam column by deflecting the ion beam to pass the electrostatic objective lens closer to the center of the electrostatic objective lens and in which a second of the one or more deflectors adjusts the impact point of the ion beam to compensate for the magnetic field outside the ion column.
Dependencies are inferred from the claim text.