Apparatus and methods for adjusting beam condition of charged particles are disclosed. According to certain embodiments, the apparatus includes one or more first multipole lenses displaced above an aperture, the one or more first multipole lenses being configured to adjust a beam current of a charged-particle beam passing through the aperture. The apparatus also includes one or more second multipole lenses displaced below the aperture, the one or more second multipole lenses being configured to adjust at least one of a spot size and a spot shape of the beam.

This charged particle beam device comprises: a charged particle beam source that generates charged particle beams; an objective lens in which coil current is inputted to focus the charged particle beams on a sample; a control unit that controls the coil current; a hysteresis characteristics storage unit that stores hysteresis characteristics information of the objective lens; a history information storage unit that stores history information relating to the coil current; and an estimating unit that estimates the magnetic field generated by the objective lens based on the coil current, the history information, and the hysteresis characteristic information, and has a magnetic field correction unit that, when the absolute value of the change amount of the coil current is greater than a prescribed value, further adds to the magnetic field estimated by the estimating unit a correction value according to the coil current and its change amount, correcting the magnetic field generated by the objective lens.

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.

Apparatus and methods for adjusting beam condition of charged particles are disclosed. According to certain embodiments, the apparatus includes one or more first multipole lenses displaced above an aperture, the one or more first multipole lenses being configured to adjust a beam current of a charged-particle beam passing through the aperture. The apparatus also includes one or more second multipole lenses displaced below the aperture, the one or more second multipole lenses being configured to adjust at least one of a spot size and a spot shape of the beam.

A scanning electron microscope comprises three objective lenses, including a distant objective lens and a close objective lens, which are of conventional type, and an immersion objective lens of the immersion type below the distant objective lens and the close objective lens. These three objective lenses can be controlled independently, therefor different combinations of active objective lenses can be achieved. The scanning electron microscope therefore offers various imaging modes. There is a possibility to switch between these imaging modes and therefore, choose the most suitable way of imaging for given application.

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.

The present invention provides an electrode assembly comprising two or more electrodes arranged around a primary axis forming a non-cylindrical channel space. General electronic apparatus/device, particularly apparatus of charged-particle beam such as electron microscope, may use the electrode assembly to create an optimized pattern of electrical field within non-cylindrical channel space. When the electrode assembly is used as a beam deflector in a magnetic objective lens, the electrical field within the central channel space can be co-optimized with the magnetic field for reducing aberration(s) such as distortion, field curvature, astigmatism, and chromatic aberration, after the beam passes through the central channel space.

A charged particle beam irradiation apparatus according to an embodiment includes: a first scanning electromagnet device configured to deflect a charged particle beam to a second direction that is substantially perpendicular to a first direction along which the charged particle beam enters, the first scanning electromagnet device having an aperture on an outlet side larger than that on an inlet side; and a second scanning electromagnet device configured to deflect the charged particle beam to a third direction that is substantially perpendicular to the first direction and the second direction, the second scanning electromagnet device having an aperture on an outlet side larger than that on an inlet side, the first scanning electromagnet device and the second scanning electromagnet device being disposed to be parallel with the first direction.

A method of controlling a transmission electron microscope includes: causing a first magnetic field lens to generate a first magnetic field and causing a second magnetic field lens to generate a second magnetic field; causing the magnetic field applying unit to generate a magnetic field of a direction along an optical axis on a specimen mounting surface; and changing excitations of the first excitation coil and the second excitation coil to correct a deviation of a focal length of an objective lens due to the magnetic field generated by the magnetic field applying unit.

A miniature electron beam column in combination with magnetostatic lenses to produce very high-performance miniature electron or ion beam columns. Silicon-based electron optical components provide high-accuracy formation and alignment of critical optical elements and the magnetic lenses provide low-aberration focusing or condensing elements. Accurate assembly of the silicon and magnetic components is achievable via the multilayered assembly techniques and allows for achieving high performance.