Electron source designs are disclosed. The emitter structure, which may be silicon, has a layer on it. The layer may be graphene or a photoemissive material, such as an alkali halide. An additional layer between the emitter structure and the layer or a protective layer on the layer can be included. Methods of operation and methods of manufacturing also are disclosed.

A photocathode can include a body fabricated of a wide bandgap semiconductor material, a metal layer, and an alkali halide photocathode emitter. The body may have a thickness of less than 100 nm and the alkali halide photocathode may have a thickness less than 10 nm. The photocathode can be illuminated with a dual wavelength scheme.

A flat top laser beam is used to generate an electron beam with a photocathode that can include an alkali halide. The flat top profile can be generated using an optical array. The laser beam can be split into multiple laser beams or beamlets, each of which can have the flat top profile. A phosphor screen can be imaged to determine space charge effects or electron energy of the electron beam.

The present invention provides a charged particle beam device with which optimal parameters for the device can be effectively derived in a short time period. This charged particle beam device comprises: an electron gun (1) that irradiates a sample (10) with an electron beam (2); an image processing unit (901) that acquires an image of the sample (10) from a signal (12) generated by the sample (10) due to the electron beam (2); a database (604) that holds correspondence between a first parameter that is an optical condition, a second parameter that is a value pertaining to device performance, and a third parameter that is information pertaining to the device configuration, and stores a plurality of analysis values and measurement values; and a learning machine (605) that searches the database (604) and derives a first parameter that satisfies a target value of the second parameter.

The charged particle beam apparatus includes a charged particle source generating a charged particle beam, a deflector deflecting the charged particle beam, a detector detecting secondary electrons emitted from an irradiation target in response to irradiation with the charged particle beam, and a processor system. The processor system (A) acquires a first time-series change in secondary electron detection-related quantity by repeatedly performing the following (A1) and (A2), (A1) directly or indirectly, maintains or changes the control amount applied to the deflector to a first control amount, and (A2) acquires the secondary electron detection-related quantity based on an output from the detector, and (B) acquires a time-series change in variation of the beam diameter of the charged particle beam based on the first time-series change.

A detector includes a set of sensing elements, first section circuitry communicatively coupling a first set of sensing elements to an input of first signal processing circuitry, second section circuitry communicatively coupling a second set of sensing elements to an input of second signal processing circuitry, and interconnection circuitry communicatively coupling an output of the first signal processing circuitry to an output of the second signal processing circuitry. The interconnection circuitry may include an interconnection layer having interconnection switching elements communicatively coupled to outputs of analog signal paths of the detector. Interconnection switching elements may communicatively couple the outputs of adjacent analog signal paths. The detector may also include signal processing circuitry that includes a plurality of converters. The interconnection circuitry may be configured to selectively couple outputs of the first and second signal processing circuitry to the converters.