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.

Proposed is a charged particle beam apparatus for the purpose of detecting a charged particle emitted from a sample in a specific direction by discriminating between the charged particle and a charged particle emitted in another direction. As one aspect of achieving the above purpose, proposed is a charged particle beam apparatus including an objective lens configured to focus a beam emitted from a charged particle source, a detector (8) configured to detect at least one of a first charged particle (23) emitted from a sample by irradiating the sample with the beam and a second charged particle emitted from a charged particle collided member by causing the first charged particle to collide with the charged particle collision member disposed on a trajectory of the first charged particle, and an electrostatic lens (12) including a plurality of electrodes disposed between the objective lens and the detector, in which the electrostatic lens is a Butler type.

Proposed is a charged particle beam apparatus for the purpose of detecting a charged particle emitted from a sample in a specific direction by discriminating between the charged particle and a charged particle emitted in another direction. As one aspect of achieving the above purpose, proposed is a charged particle beam apparatus including an objective lens configured to focus a beam emitted from a charged particle source, a detector (8) configured to detect at least one of a first charged particle (23) emitted from a sample by irradiating the sample with the beam and a second charged particle emitted from a charged particle collided member by causing the first charged particle to collide with the charged particle collision member disposed on a trajectory of the first charged particle, and an electrostatic lens (12) including a plurality of electrodes disposed between the objective lens and the detector, in which the electrostatic lens is a Butler type.

An objective lens arrangement that may include a magnetic lens and an electrostatic lens. The magnetic lens may include one or more coils, an upper polepiece and a lower polepiece. The electrostatic lens may include an upper electrode, an internal lower electrode and an external lower electrode. A majority of the internal lower electrode may be surrounded by a majority of the external lower electrode. The upper electrode, the internal lower electrode, and the external lower electrode are arranged in a coaxial relationship along an optical axis of the objective lens arrangement. An area of a bottom aperture of the external lower electrode may not exceed an area of a bottom aperture of the internal lower electrode.

An objective lens arrangement that may include a magnetic lens and an electrostatic lens. The magnetic lens may include one or more coils, an upper polepiece and a lower polepiece. The electrostatic lens may include an upper electrode, an internal lower electrode and an external lower electrode. A majority of the internal lower electrode may be surrounded by a majority of the external lower electrode. The upper electrode, the internal lower electrode, and the external lower electrode are arranged in a coaxial relationship along an optical axis of the objective lens arrangement. An area of a bottom aperture of the external lower electrode may not exceed an area of a bottom aperture of the internal lower electrode.

An objective lens arrangement includes a first, second and third pole pieces, each being substantially rotationally symmetric. The first, second and third pole pieces are disposed on a same side of an object plane. An end of the first pole piece is separated from an end of the second pole piece to form a first gap, and an end of the third pole piece is separated from an end of the second pole piece to form a second gap. A first excitation coil generates a focusing magnetic field in the first gap, and a second excitation coil generates a compensating magnetic field in the second gap. First and second power supplies supply current to the first and second excitation coils, respectively. A magnetic flux generated in the second pole piece is oriented in a same direction as a magnetic flux generated in the second pole piece.

When focus adjustment is performed according to the height of the surface of a sample at each inspection point in order to continuously inspect a plurality of inspection points on a wafer by using an electron microscope, even when the focus adjustment by an electrostatic lens in which a variation of heights of inspection points is greater than a predetermined range, and that can perform adjustment at a high speed and adjustment by an electromagnetic lens with a low speed are required to be used together, a flow of focus adjustment in which the number of times of the adjustment by the electromagnetic lens is reduced by using a relation of changes of heights at inspection points, an inspection order, and a range in which an electrostatic focus can be performed is realized, so that inspection with high throughput is made possible.

When focus adjustment is performed according to the height of the surface of a sample at each inspection point in order to continuously inspect a plurality of inspection points on a wafer by using an electron microscope, even when the focus adjustment by an electrostatic lens in which a variation of heights of inspection points is greater than a predetermined range, and that can perform adjustment at a high speed and adjustment by an electromagnetic lens with a low speed are required to be used together, a flow of focus adjustment in which the number of times of the adjustment by the electromagnetic lens is reduced by using a relation of changes of heights at inspection points, an inspection order, and a range in which an electrostatic focus can be performed is realized, so that inspection with high throughput is made possible.

There are disclosed an aberration correction method and a charged particle beam system capable of correcting off-axis first order aberrations. The aberration correction method is for use in the charged particle beam system (100) equipped with an aberration corrector (30) which has plural stages of multipole elements (32a, 32b) and a transfer lens system (34) disposed between the multipole elements (32a, 32b). The method includes varying the excitation of the transfer lens system (34) and correcting off-axis first order aberrations.

There are disclosed an aberration correction method and a charged particle beam system capable of correcting off-axis first order aberrations. The aberration correction method is for use in the charged particle beam system (100) equipped with an aberration corrector (30) which has plural stages of multipole elements (32a, 32b) and a transfer lens system (34) disposed between the multipole elements (32a, 32b). The method includes varying the excitation of the transfer lens system (34) and correcting off-axis first order aberrations.