Abstract: An electron gun used in a particle beam device, for example in an electron microscope, has a relatively good brightness and may be operated under vacuum conditions which can be easily achieved (i.e., for example, at a residual pressure of about 10?6 or 10?7 mbar). The electron gun comprises an electron source having an electron emission surface. Furthermore, the electron gun comprises a first electrode configured to control a path of electrons emitted from the electron emission surface, a second electrode which is configured to suppress emissions of electrons from a side surface of the electron source and a third electrode configured to accelerate electrons emitted from the electron source to a final energy. A first voltage, a second voltage and a third voltage are adjusted to avoid any crossover of electrons emitted from the electron emission surface.

Abstract: A particle beam device includes a particle beam generator, an objective lens, and first and second deflection systems for deflecting the particle beam in an object plane defined by the objective lens. In a first operating mode, the first deflection system generates a first deflection field and the second deflection system generates a second deflection field. In a second operating mode, the first deflection system generates a third deflection field and the second deflection system generates a fourth deflection field.

Abstract: A particle beam device includes a particle beam generator, an objective lens, and first and second deflection systems for deflecting the particle beam in an object plane defined by the objective lens. In a first operating mode, the first deflection system generates a first deflection field and the second deflection system generates a second deflection field. In a second operating mode, the first deflection system generates a third deflection field and the second deflection system generates a fourth deflection field.

Abstract: An electron gun used in a particle beam device, for example in an electron microscope, has a relatively good brightness and may be operated under vacuum conditions which can be easily achieved (i.e., for example, at a residual pressure of about 10?6 or 10?7 mbar). The electron gun comprises an electron source having an electron emission surface. Furthermore, the electron gun comprises a first electrode configured to control a path of electrons emitted from the electron emission surface, a second electrode which is configured to suppress emissions of electrons from a side surface of the electron source and a third electrode configured to accelerate electrons emitted from the electron source to a final energy. A first voltage, a second voltage and a third voltage are adjusted to avoid any crossover of electrons emitted from the electron emission surface.

Abstract: A charged particle beam instrument (10) is provided, the instrument comprising a charged particle optical column (12), a voltage source, a detector (14) and a sample holder (18), the column (12) being operable to direct a beam of primary charged particles at a sample (20) on the sample holder (18) to cause secondary charged particles to be released from the sample, the voltage source being operable to establish in the vicinity of the sample an electric field that has a component that draws the secondary charged particles towards the detector (14), and the detector being operable to detect secondary charged particles, wherein the instrument further comprises a further voltage source (16) variable between a first voltage that establishes a component of the electric field that draws the secondary charged particles away from the sample, so as to prevent at least some of them from colliding with the sample (20) or sample holder (18), and a second voltage that establishes a component of the electric field that draw

Abstract: A charged particle detector is provided for use in an electron microscope. The detector has a chamber for receiving charged particles generated by the interaction between a particle beam generated by the microscope and the sample. The chamber is maintained at at least a partial vacuum and contains an impact responsive sensor for detecting particles incident thereon. An accelerating electrode field is set up in the chamber by one or more electrodes, and the chamber is sealed by an electronically conductive barrier so as to prevent gas leaking into the chamber, whilst being sufficiently thin to enable charged particles to travel across the barrier and thereby be detected by the detector. The electrically conductive barrier enables a very large accelerating voltage to be used without causing discharge through any gaseous medium in the microscope sample chamber.

Abstract: A signal detector for detecting electrically charged particles in a gaseous medium has an electrode having a tip region for gathering charged particles. The electrode is connected to a voltage source for applying a voltage that generates electro-static field for attracting the particles to the electrode, and at least part of the tip region has a radius of curvature which is sufficiently small or (in the case of a point tip or sharp edge) infinitesimally small so as to create a localised high intensity electro-static field which defines a detection zone in which, in use, charge particles are accelerated by the electric field so as to ionise gas molecules in the zone and thus amplify the signal to be received by the detector. The received signal is supplied through an output of the detector. The detector may be provided in a sample chamber of a scanning electron microscope.

Abstract: A charged particle detector is provided for use in an electron microscope. The detector has a chamber for receiving charged particles generated by the interaction between a particle beam generated by the microscope and the sample. The chamber is maintained at at least a partial vacuum and contains an impact responsive sensor for detecting particles incident thereon. An accelerating electrode field is set up in the chamber by one or more electrodes, and the chamber is sealed by an electronically conductive barrier so as to prevent gas leaking into the chamber, whilst being sufficiently thin to enable charged particles to travel across the barrier and thereby be detected by the detector. The electrically conductive barrier enables a very large accelerating voltage to be used without causing discharge through any gaseous medium in the microscope sample chamber.

Abstract: A charged particle detector is provided for use in an electron microscope. The detector has a chamber for receiving charged particles generated by the interaction between a particle beam generated by the microscope and the sample. The chamber is maintained at at least a partial vacuum and contains an impact responsive sensor for detecting particles incident thereon. An accelerating electrode field is set up in the chamber by one or more electrodes, and the chamber is sealed by an electronically conductive barrier so as to prevent gas leaking into the chamber, whilst being sufficiently thin to enable charged particles to travel across the barrier and thereby be detected by the detector. The electrically conductive barrier enables a very large accelerating voltage to be used without causing discharge through any gaseous medium in the microscope sample chamber.

Abstract: A signal detector for detecting electrically charged particles in a gaseous medium has an electrode having a tip region for gathering charged particles. The electrode is connected to a voltage source for applying a voltage that generates electro-static field for attracting the particles to the electrode, and at least part of the tip region has a radius of curvature which is sufficiently small or (in the case of a point tip or sharp edge) infinitesimally small so as to create a localised high intensity electro-static field which defines a detection zone in which, in use, charge particles are accelerated by the electric field so as to ionise gas molecules in the zone and thus amplify the signal to be received by the detector. The received signal is supplied through an output of the detector. The detector may be provided in a sample chamber of a scanning electron microscope.

Abstract: A charged particle detector is provided for use in an electron microscope. The detector has a chamber for receiving charged particles generated by the interaction between a particle beam generated by the microscope and the sample. The chamber is maintained at at least a partial vacuum and contains an impact responsive sensor for detecting particles incident thereon. An accelerating electrode field is set up in the chamber by one or more electrodes, and the chamber is sealed by an electronically conductive barrier so as to prevent gas leaking into the chamber, whilst being sufficiently thin to enable charged particles to travel across the barrier and thereby be detected by the detector. The electrically conductive barrier enables a very large accelerating voltage to be used without causing discharge through any gaseous medium in the microscope sample chamber.