Patent classifications
H01J2237/1415
Systems and methods for electron beam focusing in electron beam additive manufacturing
A system for melting, sintering, or heat treating a material is provided. The system includes a cathode, an anode, and a focus coil assembly having a quadrupole magnet. The quadrupole magnet includes four poles and a yoke. The four poles are spaced apart and surround a beam cavity. Each of the four poles includes a pole face proximate the beam cavity and an end opposite the pole face. The first and third poles are aligned along an x-axis and configured to have a first magnetic polarity at their respective pole faces and a second magnetic polarity opposite the first magnetic polarity at their respective ends. The second and fourth poles are aligned along a y-axis and configured to have the second magnetic polarity at their respective pole faces and the first magnetic polarity at their respective ends. The yoke surrounds the poles and is coupled to the poles.
CHARGED PARTICLE SOURCE
This invention provides a charged particle source, which comprises an emitter and means fo generating a magnetic field distribution. The magnetic field distribution is minimum, about zero, or preferred zero at the tip of the emitter, and along the optical axis is maximum away from the tip immediately. In a preferred embodiment, the magnetic field distribution is provided by dual magnetic lens which provides an anti-symmetric magnetic field at the tip, such that magnetic field at the tip is zero.
Charged particle beam apparatus
The present invention provides a charged particle beam apparatus that covers a wide range of detection angles of charged particles emitted from a sample. Accordingly, the present invention proposes a charged particle beam apparatus that is provided with an objective lens for converging charged particle beams emitted from a charged particle source, and a detector for detecting charged particles emitted from a sample, wherein: the objective lens includes an inner magnetic path and an outer magnetic path which are formed so as to enclose a coil; the inner magnetic path comprises a first inner magnetic path disposed at a position opposite to an optical axis of the charged particle beams and a second inner magnetic path which is formed at a slant with respect to the optical axis of the charged particle beams and which includes a leading end of the magnetic path; and a detection surface of the detector is disposed at the outer side from a virtual straight line that passes through the leading end of the magnetic path and that is parallel to the optical axis of the charged particle beams.
Charged particle source
This invention provides a charged particle source, which comprises an emitter and means for generating a magnetic field distribution. The magnetic field distribution is minimum, about zero, or preferred zero at the tip of the emitter, and along the optical axis is maximum away from the tip immediately. In a preferred embodiment, the magnetic field distribution is provided by dual magnetic lens which provides an anti-symmetric magnetic field at the tip, such that magnetic field at the tip is zero.
Scanning magnet design with enhanced efficiency
A scanning magnet is positioned downstream of a mass resolving magnet of an ion implantation system and is configured to control a path of an ion beam downstream of the mass resolving magnet for a scanning or dithering of the ion beam. The scanning magnet has a yoke having a channel defined therein. The yoke is ferrous and has a first side and a second side defining a respective entrance and exit of the ion beam. The yoke has a plurality of laminations stacked from the first side to the second side, wherein at least a portion of the plurality of laminations associated with the first side and second side comprise one or more slotted laminations having plurality of slots defined therein.
Scanning electron microscope with objective lens below sample stage
An immersion objective lens is configured below a stage such that multiple detectors can be configured above sample for large beam current application, particularly for defect inspection. Central pole piece of the immersion objective lens thus can be provided that a magnetic monopole-like field can be provided for electron beam. Auger electron detector thus can be configured to analyze materials of sample in the defect inspection.
Magnetic lens and exciting current control method
A magnetic lens is disclosed, which includes: a magnetic yoke, an exciting coil and a power supply controlling system. The magnetic yoke is at outside of the exciting coil and surrounds the coil; the exciting coil is made up of litz wires; the power supply controlling system is arranged to supply power to the exciting coil and control the flow directions and magnitudes of the currents in the exciting coil. A method for controlling the magnetic lens is also disclosed.
Charged Particle Beam Device
The present invention provides a charged particle beam apparatus capable of efficiently reducing the effect of a residual magnetic field when SEM observation is performed. The charged particle beam apparatus according to the present invention includes a first mode for passing a direct current to a second coil after turning off a first coil, and a second mode for passing an alternating current to the second coil after turning off the first coil.
OBJECTIVE LENS ARRANGEMENT USABLE IN PARTICLE-OPTICAL SYSTEMS
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.
Scanning Electron Microscope
An immersion objective lens is configured below a stage such that multiple detectors can be configured above sample for large beam current application, particularly for defect inspection. Central pole piece of the immersion objective lens thus can be provided that a magnetic monopole-like field can be provided for electron beam. Auger electron detector thus can be configured to analyze materials of sample in the defect inspection.