A multi-beam electron-optical system for a charged-particle assessment tool, the system comprising: a plurality of control lenses, a plurality of objective lenses and a controller. The plurality of control lenses are configured to control a parameter of a respective sub-beam. The plurality of objective lenses are configured to project one of the plurality of charged-particle beams onto a sample. The controller controls the control lenses and the objective lenses so that the charged particles are incident on the sample with a desired landing energy, demagnification and/or beam opening angle.

When a high-performance retarding voltage applying power supply cannot be employed in terms of costs or device miniaturization, it is difficult to sufficiently adjust focus in a high acceleration region within a range of changing an applied voltage, and identify a point at which a focus evaluation value is maximum. To address the above problems, a scanning electron microscope is provided including: an objective lens configured to converge an electron beam emitted from an electron source; a current source configured to supply an excitation current to the objective lens; a negative-voltage applying power supply configured to form a decelerating electric field of the electron beam on a sample; a detector configured to detect charged particles generated when the electron beam is emitted to the sample; and a control device configured to calculate a focus evaluation value from an image formed according to an output of the detector. The control device calculates a focus evaluation value when an applied voltage is changed, determines whether to increase or decrease an excitation current according to an increase or a decrease of the focus evaluation value, and supplies the excitation current based on a result of the determination.

A charged-particle assessment tool comprising: a condenser lens array, a collimator, a plurality of objective lenses and an electric power source. The condenser lens array configured to divide a beam of charged particles into a plurality of sub-beams and to focus each of the sub-beams to a respective intermediate focus. The collimator being at each intermediate focus and configured to deflect a respective sub-beam so that it is incident on the sample substantially normally. The plurality of objective lenses, each configured to project one of the plurality of charged-particle beams onto a sample. Each objective lens comprises: a first electrode; and a second electrode that is between the first electrode and the sample. The electric power source configured to apply first and second potentials to the first and second electrodes respectively such that the respective charged-particle beam is decelerated to be incident on the sample with a desired landing energy.

A charged particle assessment tool including: an objective lens configured to project a plurality of charged particle beams onto a sample, the objective lens having a sample-facing surface defining a plurality of beam apertures through which respective ones of the charged particle beams are emitted toward the sample; and a plurality of capture electrodes, each capture electrode adjacent a respective one of the beam apertures, configured to capture charged particles emitted from the sample.

Provided herein are approaches for in-situ plasma cleaning of ion beam optics. In one approach, a system includes a component (e.g., a beam-line component) of an ion implanter processing chamber. The system further includes a power supply for supplying a first voltage and first current to the component during a processing mode and a second voltage and second current to the component during a cleaning mode. The second voltage and current are applied to one or more conductive beam optics of the component, individually, to selectively generate plasma around one or more of the one or more conductive beam optics. The system may further include a flow controller for adjusting an injection rate of an etchant gas supplied to the beam-line component, and a vacuum pump for adjusting pressure of an environment of the beam-line component.

Provided is a particle beam apparatus capable of performing appropriate switching selectively between charged particle beam and neutral particle beam. A particle beam column (19) includes an ion source (41), a condenser lens (52), a charge exchange grid (55), and an objective lens (56). The ion source (41) generates ions. The condenser lens (52) changes focusing of the ion beam so that switching is performed between ion beam and neutral beam as particle beam with which a sample (S) is irradiated. The charge exchange grid (55) converts at least a part of ion beam into neutral particle beam through neutralization. The objective lens (56) is placed downstream of the charge exchange grid (55). The objective lens (56) reduces the ion beam toward the sample (S) when the sample (S) is irradiated with the neutral particle beam as the particle beam.

An electromagnetic compound lens may be configured to focus a charged particle beam. The compound lens may include an electrostatic lens provided on a secondary optical axis and a magnetic lens also provided on the secondary optical axis. The magnetic lens may include a permanent magnet. A charged particle optical system may include a beam separator configured to separate a plurality of beamlets of a primary charged particle beam generated by a source along a primary optical axis from secondary beams of secondary charged particles. The system may include a secondary imaging system configured to focus the secondary beams onto a detector along the secondary optical axis. The secondary imaging system may include the compound lens.

A deceleration apparatus capable of decelerating a short spot beam or a tall ribbon beam is disclosed. In either case, effects tending to degrade the shape of the beam profile are controlled. Caps to shield the ion beam from external potentials are provided. Electrodes whose position and potentials are adjustable are provided, on opposite sides of the beam, to ensure that the shape of the decelerating and deflecting electric fields does not significantly deviate from the optimum shape, even in the presence of the significant space-charge of high current low-energy beams of heavy ions.

When a high-performance retarding voltage applying power supply cannot be employed in terms of costs or device miniaturization, it is difficult to sufficiently adjust focus in a high acceleration region within a range of changing an applied voltage, and identify a point at which a focus evaluation value is maximum. To address the above problems, a scanning electron microscope is provided including: an objective lens configured to converge an electron beam emitted from an electron source; a current source configured to supply an excitation current to the objective lens; a negative-voltage applying power supply configured to form a decelerating electric field of the electron beam on a sample; a detector configured to detect charged particles generated when the electron beam is emitted to the sample; and a control device configured to calculate a focus evaluation value from an image formed according to an output of the detector. The control device calculates a focus evaluation value when an applied voltage is changed, determines whether to increase or decrease an excitation current according to an increase or a decrease of the focus evaluation value, and supplies the excitation current based on a result of the determination.

In a charged particle beam device including a deceleration optical system, a change in a deceleration electric field and an axis shift due to a structure between an objective lens and a sample are prevented to reduce adverse effects on an irradiation system and detection system. The charged particle beam device includes an electron source, an objective lens configured to focus a probe electron beam from the electron source on the sample, an acceleration electrode configured to accelerate the probe electron beam, a first detector provided in the acceleration electrode, a deceleration electrode configured to form a deceleration electric field for the probe electron beam with the acceleration electrode, the probe electron beam being configured to pass through an opening of the deceleration electrode, and a second detector inserted between the deceleration electrode and the sample. The second detector includes an opening portion larger than the opening of the deceleration electrode, and a sensing surface is provided around the opening portion.