Fei Comapny

William Ralph Knowles

Milos Toth

Hendrik Nicolaas Slingerland

Marek Uncovsky

Rae Knowles, Legal Representative

Jacob Johannes Scholtz

Bradley Lamar Thiel

Gerardus Van Veen

Rene Peter Marie Schroemges

The invention relates to a particle-optical apparatus with a predetermined final vacuum pressure. To that end a vacuum chamber of said apparatus is via a first restriction connected to a volume where vapor or gas is present at a known pressure and via a second restriction to a vacuum pump. By making the ratio of the two conductances, associated with said restrictions, a calibrated ratio, the final pressure of the vacuum chamber is a predetermined final pressure. This eliminates the need for e.g. vacuum gauges and control systems, resulting in a more compact design of such apparatus.

Particle optical apparatus with a predetermined final vacuum pressure

The current invention includes methods and apparatuses for processing, that is, altering and imaging, a sample in a high pressure charged particle beam system. Embodiments of the invention include a cell in which the sample is positioned during high pressure charged particle beam processing. The cell reduces the amount of gas required for processing, thereby allowing rapid introduction, exhaustion, and switching between gases and between processing and imaging modes. Maintaining the processes gases within the cell protects the sample chamber and column from contact with the gases. In some embodiments, the temperature of the cell walls and the sample can be controlled.

High pressure charged particle beam system

A scanning transmission electron microscope operated with the sample in a high pressure environment. A preferred detector uses gas amplification by converting either scattered or unscattered transmitted electrons to secondary electrons for efficient gas amplification.

Scanning transmission electron microscope using gas amplification

A novel detector for a charged particle beam system which includes multiple gas amplification stages. The stages are typically defined by conductors to which voltage are applied relative to the sample or to a previous stage. By creating cascades of secondary electrons in multiple stages, the gain can be increased without causing dielectric breakdown of the gas.

Multistage gas cascade amplifier

A particle-optical apparatus, such as an ESEM&#xae;, for simultaneous observing a sample with particles and photons. A pressure limiting aperture (PLA) is placed in a diaphragm between the objective lens of the ESEM&#xae; and the sample position. The distance between the sample position and the aperture is sufficiently small to allow a large collection angle of the photons through this aperture. A mirror is placed between the diaphragm and the objective lens. Due to the large collection angle for photons a large NA is achieved. The small distance between sample position and aperture also result in less scattering of electrons than occurs in ESEM's where a mirror is placed between aperture and sample position, as the electrons have to travel through only a limited length in a high pressure area. Embodiments describe combinations where e.g. an immersion lens is used.

Particle-optical apparatus for simultaneous observing a sample with particles and photons

A detector for use with a high pressure SEM, such as an ESEM&#xae; environmental SEM from FEI Company, extends the effective detection space above the PLA, thereby increasing secondary signal amplification without increasing working distance or pressure. Embodiments can therefore provide improved resolution and can operate at lower gas pressures.

Detector for charged particle beam instrument

A particle-optical apparatus comprising a sample holder for receiving a sample, a particle source embodied to produce a primary beam of first electrically charged particles along an optical axis for the purpose of irradiating the sample, first detector embodied to detect second electrically charged particles that emanate from the sample as a result of the irradiation thereof, a detection space that at the least is formed by the sample holder and the first detector, and an immersion lens embodied to produce a magnetic field for the purpose of focusing the primary beam in the vicinity of the sample holder. The first detector are embodied to produce an electric field in the detection space, and the detection space is embodied to comprise a gas.

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Forest Grove, OR, United States of America

William Ralph Knowles