An electron gun includes: a cathode, which has a cathode holder and a cathode body; and a Wehnelt cylinder. The cathode holder receives the cathode body and the Wehnelt cylinder is suitable for bundling free electrons, which can escape from the cathode body toward the Wehnelt cylinder, to form an electron beam. The Wehnelt cylinder is interlockingly arranged, at least in some parts along a first inner surface facing the cathode holder, on an outer surface of the cathode holder and at least partly extends around the cathode holder.

Disclosed are a filament positioning system and a filament positioning method. The filament positioning system includes a bottom plate, a first positioning regulating mechanism and a second positioning regulating mechanism, wherein the first positioning regulating mechanism is configured to conduct positioning regulation of a position of a filament seat on the bottom plate, so that filament seats of different models can be fixed to the bottom plate, and the second positioning regulating mechanism is configured to conduct positioning regulation on the filament; and a detection module configured to collect and display position information of a filament tip and the filament seat, wherein the first positioning regulating mechanism and the second positioning regulating mechanism correspondingly regulate positions of the filament seat and the filament tip according to the position information.

Disclosed are a filament positioning system and a filament positioning method. The filament positioning system includes a bottom plate, a first positioning regulating mechanism and a second positioning regulating mechanism, wherein the first positioning regulating mechanism is configured to conduct positioning regulation of a position of a filament seat on the bottom plate, so that filament seats of different models can be fixed to the bottom plate, and the second positioning regulating mechanism is configured to conduct positioning regulation on the filament; and a detection module configured to collect and display position information of a filament tip and the filament seat, wherein the first positioning regulating mechanism and the second positioning regulating mechanism correspondingly regulate positions of the filament seat and the filament tip according to the position information.

A charged particle microscope and a method of operating a charged particle microscope are disclosed. The microscope employs a source for producing charged particles, and a source lens below the source to form a charged particle beam which is directed onto a specimen by a condenser system. A detector collects radiation emanating from the specimen in response to irradiation of the specimen by the beam. The source lens is a compound lens, focusing the beam within a vacuum enclosure using both a magnetic lens having permanent magnets outside the enclosure to produce a magnetic field at the beam, and a variable electrostatic lens within the enclosure.

A magnetic gun lens and an electrostatic gun lens can be used in an electron beam apparatus and can help provide high resolutions for all usable electron beam currents in scanning electron microscope, review, and/or inspection uses. An extracted beam can be directed at a wafer through a beam limiting aperture using the magnetic gun lens. The electron beam also can pass through an electrostatic gun lens after the electron beam passes through the beam limiting aperture.

A scanning electron microscopy (SEM) system includes a plurality of electron-optical columns and a plurality of electron beam sources. The electron beam sources include an emitter including one or more emitter tips configured to generate one or more electron beams of a plurality of electron beams. The electron beam sources include a stack of one or more positioners configured to adjust a position of the emitter based on one or more measurements of the electron beam generated by the emitter. The emitter is configured to scan the one or more electron beams across an area surrounding a bore of an electron-optical column of the plurality of electron-optical columns. The electron beam source array includes a carrier plate and a source tower. The source tower is configured to adjust a position of the plurality of electron beam sources relative to a position of the plurality of electron-optical columns.

Examples of an electron gun with a moving cathode station and a moving anode station are described. The moving cathode has a driver that moves the station and comprises a plurality of cathodes with a plurality of bias cups to control a thermal electron emission region by applying a bias voltage to the bias cup. The moving anode station comprises a plurality of anodes and has driver to move the anode station such that a position of each anode is synchronized with a positioned of a respective matching pair of cathode and bias cup. A controller that is in communication with the anode and cathode moving stations controls the bias voltage and the drivers to control the amount of thermal electrons and to synchronize and align a predetermined cathode with a predetermined anode thus controlling the size and parameters of the generated electron beam.

Examples of an electron gun with a moving cathode station and a moving anode station are described. The moving cathode has a driver that moves the station and comprises a plurality of cathodes with a plurality of bias cups to control a thermal electron emission region by applying a bias voltage to the bias cup. The moving anode station comprises a plurality of anodes and has driver to move the anode station such that a position of each anode is synchronized with a positioned of a respective matching pair of cathode and bias cup. A controller that is in communication with the anode and cathode moving stations controls the bias voltage and the drivers to control the amount of thermal electrons and to synchronize and align a predetermined cathode with a predetermined anode thus controlling the size and parameters of the generated electron beam.

Examples of an electron gun with a moving cathode station and a moving anode station are described. The moving cathode has a driver that moves the station and comprises a plurality of cathodes with a plurality of bias cups to control a thermal electron emission region by applying a bias voltage to the bias cup. The moving anode station comprises a plurality of anodes and has driver to move the anode station such that a position of each anode is synchronized with a positioned of a respective matching pair of cathode and bias cup. A controller that is in communication with the anode and cathode moving stations controls the bias voltage and the drivers to control the amount of thermal electrons and to synchronize and align a predetermined cathode with a predetermined anode thus controlling the size and parameters of the generated electron beam.

Examples of an electron gun with a moving cathode station and a moving anode station are described. The moving cathode has a driver that moves the station and comprises a plurality of cathodes with a plurality of bias cups to control a thermal electron emission region by applying a bias voltage to the bias cup. The moving anode station comprises a plurality of anodes and has driver to move the anode station such that a position of each anode is synchronized with a positioned of a respective matching pair of cathode and bias cup. A controller that is in communication with the anode and cathode moving stations controls the bias voltage and the drivers to control the amount of thermal electrons and to synchronize and align a predetermined cathode with a predetermined anode thus controlling the size and parameters of the generated electron beam.