A multi-beam apparatus for observing a sample with high resolution and high throughput is proposed. In the apparatus, a source-conversion unit changes a single electron source into a virtual multi-source array, a primary projection imaging system projects the array to form plural probe spots on the sample, and a condenser lens adjusts the currents of the plural probe spots. In the source-conversion unit, the image-forming means is on the upstream of the beamlet-limit means, and thereby generating less scattered electrons. The image-forming means not only forms the virtual multi-source array, but also compensates the off-axis aberrations of the plurality of probe spots.

A multi-beam generation unit for a multi-beam system has larger individual focusing power for each of a plurality of primary charged particle beamlets. The multi-beam generation unit comprises an active terminating multi-aperture plate. The terminating multi-aperture plate can be used for a larger focusing range for an individual stigmatic focus spot adjustment of each beamlet of a plurality of primary charged particle beamlets.

These electron beam separator designs address thermally-induced beam drift in an electron-optical system. A heater coil wrapped around the beam separator unit can maintain constant power. Additional coils also can be wrapped around the beam separator in a bifilar manner, which can maintain constant power in the beam separator coils. Wien power can be determined, and then heater coil current can be determined.

These electron beam separator designs address thermally-induced beam drift in an electron-optical system. A heater coil wrapped around the beam separator unit can maintain constant power. Additional coils also can be wrapped around the beam separator in a bifilar manner, which can maintain constant power in the beam separator coils. Wien power can be determined, and then heater coil current can be determined.

A multi-beam apparatus for observing a sample with high resolution and high throughput is proposed. In the apparatus, a source-conversion unit changes a single electron source into a virtual multi-source array, a primary projection imaging system projects the array to form plural probe spots on the sample, and a condenser lens adjusts the currents of the plural probe spots. In the source-conversion unit, the image-forming means is on the upstream of the beamlet-limit means, and thereby generating less scattered electrons. The image-forming means not only forms the virtual multi-source array, but also compensates the off-axis aberrations of the plurality of probe spots.

A charged particle beam device is described, which includes: a beam source configured to generate a charged particle beam propagating along an optical axis (A); an aperture device with a first number of apertures configured to create a first number of beamlets from the charged particle beam, wherein the first number is five or more, wherein the apertures are arranged on a ring line around the optical axis (A) such that perpendiculars of the apertures onto a tangent of the ring line are evenly spaced. The charged particle beam device further includes an electrostatic multipole device configured to individually influence the beamlets. Further, a charged particle beam influencing device and a method of operating a charged particle beam device are described.

The present disclosure describes an image forming element having a semiconductor chip with micro-electro-mechanical-system (MEMS) devices and voltage generators, each voltage generator being configured to generate a voltage used by one or more of the MEMS devices. A floating ground may be used to add a voltage to the voltage generated by the voltage generators. The semiconductor chip may include electrical connections, where each voltage generator is configured to provide the voltage to the one or more MEMS devices through the electrical connections. The MEMS devices may define a boundary in the semiconductor chip within which the MEMS devices, the voltage generators, and the electrical connections are located. Each MEMS device may generate an electrostatic field to manipulate an electron beamlet of a multi-beam charged particle microscope. The MEMS devices may be organized into groups based on a distance to a reference location (e.g., optical axis) in the semiconductor chip.

A multi-beam apparatus for observing a sample with high resolution and high throughput is proposed. In the apparatus, a source-conversion unit changes a single electron source into a virtual multi-source array, a primary projection imaging system projects the array to form plural probe spots on the sample, and a condenser lens adjusts the currents of the plural probe spots. In the source-conversion unit, the image-forming means is on the upstream of the beamlet-limit means, and thereby generating less scattered electrons. The image-forming means not only forms the virtual multi-source array, but also compensates the off-axis aberrations of the plurality of probe spots.

A charged particle beam device is described, which includes: a beam source configured to generate a charged particle beam propagating along an optical axis (A); an aperture device with a first number of apertures configured to create a first number of beamlets from the charged particle beam, wherein the first number is five or more, wherein the apertures are arranged on a ring line around the optical axis (A) such that perpendiculars of the apertures onto a tangent of the ring line are evenly spaced. The charged particle beam device further includes an electrostatic multipole device configured to individually influence the beamlets. Further, a charged particle beam influencing device and a method of operating a charged particle beam device are described.

A charged particle beam device for inspection of a specimen with an array of primary charged particle beamlets is described. The charged particle beam device includes a charged particle beam source to generate a primary charged particle beam; a multi-aperture plate having at least two openings to generate an array of charged particle beamlets having at least a first beamlet having a first resolution on the specimen and a second beamlet having a second resolution on the specimen; an aberration correction element to correct at least one of spherical aberrations and chromatic aberrations of rotational symmetric charged particle lenses; and an objective lens assembly for focusing each primary charged particle beamlet of the array of primary charged particle beamlets onto a separate location on the specimen.