A light modulated electron source utilizes a photon-beam source to modulate the emission current of an electron beam emitted from a silicon-based field emitter. The field emitter's cathode includes a protrusion fabricated on a silicon substrate and having an emission tip covered by a coating layer. An extractor generates an electric field that attracts free electrons toward the emission tip for emission as part of the electron beam. The photon-beam source generates a photon beam including photons having an energy greater than the bandgap of silicon, and includes optics that direct the photon beam onto the emission tip, whereby each absorbed photon creates a photo-electron that combines with the free electrons to enhance the electron beam's emission current. A controller modulates the emission current by controlling the intensity of the photon beam applied to the emission tip. A monitor measures the electron beam and provides feedback to the controller.

A device for generating a source current of charge carriers and a method for stabilizing a source current of charge carriers are disclosed. In an embodiment the device includes at least one field emission element configured to emit charge carriers, which lead to an emission current in the field emission element, at least one extraction electrode configured to apply an extraction voltage in order to extract the charge carriers from the field emission element, wherein a first part of the extracted charge carriers contributes to the source current, and a second part of the extracted charge carriers impinges on the extraction electrode and leads to an extraction current in the extraction electrode and a control device configured to reduce fluctuations of a controlled variable Q which is a characteristic for the source current, wherein Q is a function of a difference between the emission current and the extraction current.

The present disclosure provides a method of manufacturing an electron source. The method includes forming one or more fixed emission sites on at least one needle tip, the fixed emission sites including a reaction product formed by metal atoms on a surface of the needle tip and gas molecules.

The present disclosure provides an electron source, including one or more tips, wherein at least one of the tips comprises one or more fixed emission sites, wherein at least one of the tips includes one or more fixed emission sites, wherein the emission sites includes a reaction product of metal atoms on a surface of the tip with gas molecules.

The present disclosure provides a method of regenerating an electron source, the electron source including at least one emission site fixed on a needle tip, and the emission site including a reaction product formed by metal atoms and gas molecules. The method includes regenerating the electron source in situ if an emission capability of the electron source satisfies a regeneration condition.

An electron gun for an electron microscope or similar device includes a field emitter cathode having a field emitter protrusion extending from the output surface of a monocrystalline silicon substrate, and electrodes configured to enhance the emission of electrons from a tip portion of the field emitter protrusion to generate a primary electron beam. A thin, contiguous SiC layer is disposed directly on at least the tip portion of the field emitter protrusion using a process that minimizes oxidation and defects in the SiC layer. Optional gate layers may be placed at, slightly lower than or slightly higher than the height of the field emitter tip portion to achieve high emission current and fast and accurate control of the primary emission beam. The field emitter can be p-type doped and configured to operate in a reverse bias mode, or the field emitter can be n-type doped.

A charged particle assessment tool includes: an objective lens configured to project a plurality of charged particle beams onto a sample, the objective lens having a sample-facing surface defining a plurality of beam apertures through which respective ones of the charged particle beams are emitted toward the sample; and a plurality of capture electrodes adjacent respective ones of the beam apertures and configured to capture charged particles emitted from the sample.

A device for generating a source current of charge carriers and a method for stabilizing a source current of charge carriers are disclosed. In an embodiment the device includes at least one field emission element configured to emit charge carriers, which lead to an emission current in the field emission element, at least one extraction electrode configured to apply an extraction voltage in order to extract the charge carriers from the field emission element, wherein a first part of the extracted charge carriers contributes to the source current, and a second part of the extracted charge carriers impinges on the extraction electrode and leads to an extraction current in the extraction electrode and a control device configured to reduce fluctuations of a controlled variable Q which is a characteristic for the source current, wherein Q is a function of a difference between the emission current and the extraction current.

An electron gun for an electron microscope or similar device includes a field emitter cathode having a field emitter protrusion extending from the output surface of a monocrystalline silicon substrate, and electrodes configured to enhance the emission of electrons from a tip portion of the field emitter protrusion to generate a primary electron beam. A thin, contiguous SiC layer is disposed directly on at least the tip portion of the field emitter protrusion using a process that minimizes oxidation and defects in the SiC layer. Optional gate layers may be placed at, slightly lower than or slightly higher than the height of the field emitter tip portion to achieve high emission current and fast and accurate control of the primary emission beam. The field emitter can be p-type doped and configured to operate in a reverse bias mode, or the field emitter can be n-type doped.

Methods and systems for direct atomic layer etching and deposition on or in a substrate using charged particle beams. Electrostatically-deflected charged particle beam columns can be targeted in direct dependence on the design layout database to perform atomic layer etch and atomic layer deposition, expressing pattern with selected 3D-structure. Reducing the number of process steps in patterned atomic layer etch and deposition reduces manufacturing cycle time and increases yield by lowering the probability of defect introduction. Local gas and photon injectors and detectors are local to corresponding columns, and support superior, highly-configurable process execution and control.