There is provided a scanning electron microscope which has a sample chamber capable of being evacuated to a low vacuum. The scanning electron microscope includes an electron gun for emitting an electron beam, an objective lens for focusing the emitted beam onto a sample, and a sample chamber in which the sample is housed. The objective lens includes an inner polepiece, an outer polepiece disposed outside the inner polepiece and facing the sample chamber, at least one through-hole extending through the inner and outer polepieces, and at least one cover member that closes off the through-hole. An opening is formed between the inner polepiece and the outer polepiece. The objective lens causes leakage of magnetic field from the opening toward the sample. The sample chamber has a degree of vacuum lower than that in an inner space that forms an electron beam path inside the inner polepiece.

A pulsed generator of electrically charged particles includes a vacuum chamber; wherein the vacuum chamber is configured to maintain an internal operating pressure between 10-6 mbar and atmospheric pressure; the vacuum chamber is configured to accommodate a photocathode and an anode, the photocathode and the anode being separated by an adjustable distance less than or equal to 30 mm; the vacuum chamber includes a window enabling pulsed light to reach firstly a rear face of the photocathode; the anode is arranged downstream of the photocathode and has an orifice suitable for the passage of electrically charged particles; the generator of electrically charged particles includes a system to apply a difference in potential between the photocathode and the anode, the voltage being configured to accelerate the charged particles.

A particle beam system comprises a particle beam column, a detection system and a controller. The particle beam column is configured to generate a particle beam and to direct it onto a sample, as a result of which charged particles are emitted by the sample. The detection system detects charged particles and comprises: an electrode, which can accelerate the charged particles; a potential source, which applies an adjustable electrical potential to the electrode; a scintillator; and a light detector, which outputs a detection signal. The controller controls the potential source and is configured to change the potential on the basis of the detection signal such that the scintillator operates outside its saturation and such that the light detector operates outside its saturation.

Improved is the reliability of sample analysis performed using a charged particle beam apparatus.

The charged particle beam apparatus includes region setting means for setting an irradiation region for irradiating a sample with an electron beam and an irradiation prohibited region for prohibiting the irradiation of the sample with the electron beam using a low-magnification image of the sample captured under low vacuum. In addition, the charged particle beam apparatus includes captured image acquisition means for selectively irradiating the irradiation region with the electron beam with the inside of a sample chamber under high-vacuum and acquiring a high-vacuum SEM image of the irradiation region based on the secondary or backscattered electrons emitted from the irradiation region.

Disclosed is a charged particle optical apparatus, which includes a particle optical arrangement, configured to define a particle beam path for inspecting an object. The object is accommodated in a pressure-controlled interior of a specimen chamber during the inspection of the object. The charged particle optical apparatus further includes a differential pressure module having a differential pressure aperture. A positioning arm is arranged in the specimen chamber for selectively position the differential pressure module within the pressure-controlled interior of the specimen chamber into an operating position in which the particle beam path passes through the differential pressure aperture. The selective positioning includes an advancing movement of the differential pressure module toward the primary particle beam path. The advancing movement is transmitted to the differential pressure module by a track-guided movement of the positioning arm.

An aperture device (31) is described, which is attachable to a lens system (13). The lens system (13) is arranged to form a particle beam of charged particles, emitted from a sample surface (Ss).The aperture device (31) comprises an end surface (S) which is to be arranged facing the sample surface (Ss), at least one aperture (38) arranged in the end surface (S), a length axis (32) which extends through the centre of said at least one aperture (38), and at least one gas outlet (10), which is arranged at a transverse distance (T) perpendicular from the length axis (32), and is arranged to direct gas into a volume between at least one aperture (38) and the sample surface (Ss). The end surface (S) within a distance, equal to 1/3 of the transverse distance (T), perpendicular from the length axis (32) has a variation along the length axis (32) being smaller than 1/6 of the transverse distance (T).

Various methods and systems are provided for imaging a sample under low vacuum with a charged particle beam. A magnetic field is provided in a detection area of the detector. Gas and plasma are provided in the detection area while detecting charged particles emitted from the sample. Sample image is formed based on the detected charged particles.

The present invention provides an electron microscope and an observation method capable of observing secondary electrons in the atmosphere. In detail, a charged particle microscope of the invention includes: a partition wall that separates a non-vacuum space in which a sample is loaded from a vacuum space inside a charged particle optical lens barrel; an upper electrode; a lower electrode on which the sample is loaded; a power supply for applying a voltage to at least one of the upper electrode and the lower electrode; a sample gap adjusting mechanism for adjusting a gap between the sample and the partition wall; and an image forming unit for forming an image of the sample based on the current absorbed by the lower electrode. The secondary electrons are selectively measured by using an amplification effect due to ionization collision between electrons and gas molecules generated when a voltage is applied between the upper electrode and the lower electrode. As a detection method, a method is used which measures a current value flowing in a substrate.

Various methods and systems are provided for imaging a sample under low vacuum with a charged particle beam. A magnetic field is provided in a detection area of the detector. Gas and plasma are provided in the detection area while detecting charged particles emitted from the sample. Sample image is formed based on the detected charged particles.

Techniques of using a Transmission Charged Particle Microscope for diffraction pattern detection are disclosed. An example method including irradiating at least a portion of a specimen with a charged particle beam, using an imaging system to collect charged particles that traverse the specimen during said irradiation, and to direct them onto a detector configured to operate in a particle counting mode, using said detector to record a diffraction pattern of said irradiated portion of the specimen, recording said diffraction pattern iteratively in a series of successive detection frames, and during recording of each frame, using a scanning assembly for causing relative motion of said diffraction pattern and said detector, so as to cause each local intensity maximum in said pattern to trace out a locus on said detector.