A particle beam apparatus includes a first aperture unit having an adjustable aperture opening. The particle beam apparatus may include a first condenser lens having a first pole shoe and a second pole shoe. Both the first pole shoe and the second pole shoe may be adjustable relative to a second aperture unit independently of each other. The second aperture unit may be designed as a pressure stage aperture separating a first area having a vacuum at a first pressure, and a second area having a vacuum at a second pressure. Additionally, a method for adjusting a beam current in a particle beam apparatus is provided.

The invention relates to a transmission charged particle microscope comprising a charged particle beam source for emitting a charged particle beam, a sample holder for holding a sample, an illuminator for directing the charged particle beam emitted from the charged particle beam source onto the sample, and a control unit for controlling operations of the transmission charged particle microscope. As defined herein, the transmission charged particle microscope is arranged for operating in at least two modes that substantially yield a first magnification whilst keeping said diffraction pattern substantially in focus. Said at least two modes comprise a first mode having first settings of a final projector lens of a projecting system; and a second mode having second settings of said final projector lens.

The invention relates to a screening method. The method comprises the step of providing a sample, wherein said sample comprises a sample carrier with a surface structure, as well as an object of interest. The method further comprises the step of acquiring an image of said sample. According to the disclosure, the method comprises the steps of providing information on said surface structure of said sample carrier, which may in particular comprise the step of acquiring an image of said sample carrier. In that case two images are obtained: one more sensitive to the objects of interest, and one more sensitive to the surface structure of the sample carrier. This allows manipulation of the acquired image, using said information on the surface structure of the sample carrier. With this, said manipulated image may be screened for easy and reliable detection of said object of interest.

A multi-beam apparatus for observing a sample with high resolution and high throughput is proposed. In the apparatus, a source-conversion unit forms plural and parallel images of one single electron source by deflecting plural beamlets of a parallel primary-electron beam therefrom, and one objective lens focuses the plural deflected beamlets onto a sample surface and forms plural probe spots thereon. A movable condenser lens is used to collimate the primary-electron beam and vary the currents of the plural probe spots, a pre-beamlet-forming means weakens the Coulomb effect of the primary-electron beam, and the source-conversion unit minimizes the sizes of the plural probe spots by minimizing and compensating the off-axis aberrations of the objective lens and condenser lens.

A charged particle beam system is disclosed, comprising: a charged particle beam generator for generating a beam of charged particles; a charged particle optical column arranged in a vacuum chamber, wherein the charged particle optical column is arranged for projecting the beam of charged particles onto a target, and wherein the charged particle optical column comprises a charged particle optical element for influencing the beam of charged particles; a source for providing a cleaning agent; a conduit connected to the source and arranged for introducing the cleaning agent towards the charged particle optical element;

wherein the charged particle optical element comprises: a charged particle transmitting aperture for transmitting and/or influencing the beam of charged particles, and at least one vent hole for providing a flow path between a first side and a second side of the charged particle optical element,

wherein the vent hole has a cross section which is larger than a cross section of the charged particle transmitting aperture.

Further, a method for preventing or removing contamination in the charged particle transmitting apertures is disclosed, comprising the step of introducing the cleaning agent while the beam generator is active.

Methods for using electron diffraction holography to investigate a sample, according to the present disclosure include the initial steps of emitting a plurality of electrons toward the sample, forming the plurality of electrons into a first electron beam and a second electron beam, and modifying the focal properties of at least one of the two beams such that the two beams have different focal planes. Once the two beams have different focal planes, the methods include focusing the first electron beam such that it has a focal plane at or near the sample, and focusing the second electron beam so that it is incident on the sample, and has a focal plane in the diffraction plane. An interference pattern of the first electron beam and the diffracted second electron beam is then detected in the diffraction plane, and then used to generate a diffraction holograph.

Methods and systems for investigating a sample using a dual beam bifocal charged particle microscope, according to the present disclosure include emitting a plurality of charged particles toward the sample, forming the plurality of charged particles into a first charged particle beam and a second charged particle beam, and modifying the focal properties of at least one of the first charged particle beam and the second charged particle beam. The focal properties of at least one of the first charged particle beam and the second charged particle beam is modified such that the corresponding focal planes of the first charged particle beam and the second charged particle beam are different.

Methods for using a single electron microscope system for investigating a sample with TEM and STEM techniques include the steps of emitting electrons toward the sample, forming the electrons into a two beams, and then modifying the focal properties of at least one of the two beams such that they have different focal planes. Once the two beams have different focal planes, the first electron beam is focused such that it acts as a STEM beam that is focused at the sample, and the second electron beam is focused so that it acts as a TEM beam that is parallel beam when incident on the sample. Emissions resultant from the STEM beam and the TEM beam being incident on the sample can then be detected by a single detector or detector array and used to generate a TEM image and a STEM image.

A transmission electron microscope includes an electron beam source emitting an electron beam and an illumination optical system for directing the emitted electron beam at a sample. The illumination optical system has a first condenser lens, a second condenser lens, a third condenser lens, a fourth condenser lens, an objective lens, and a condenser aperture disposed at the position of the second condenser lens. The third condenser lens and the fourth condenser lens cooperate to make the position of the condenser aperture and a sample plane conjugate to each other. The first condenser lens and the second condenser lens cooperate to make the electron beam source and a front focal plane of the objective lens conjugate to each other while the conjugate relationship between the position of the condenser aperture and the sample plane is maintained by the third and fourth condenser lenses.

A plasma measuring apparatus includes: a chamber; a stage provided inside the chamber; a plasma generation source configured to generate plasma in the chamber; an inorganic electroluminescence (EL) substrate placed on the stage and configured to emit light when an electric field is applied; a transmission window provided in the chamber and configured to transmit light; a spectroscope disposed outside the chamber and configured to measure a light emission of the inorganic EL substrate through the transmission window; and a controller configured to measure an ion energy from a result of the measurement by the spectroscope.