A method for inspecting a sample by means of a multi-beam charged particle inspection apparatus, and an apparatus for performing this method are provided. The multi-beam charged particle inspection apparatus is configured to project an array of charged particle beamlets within an exposure area on the sample. The apparatus includes a detection system for detecting X-Rays and/or cathodoluminescent light from the exposure area emitted by the sample due to an interaction of the array of charged particle beamlets with the sample. The method includes the steps of projecting the array of charged particle beamlets within the exposure area on the sample, and monitoring a combined emission of X-Rays and/or cathodoluminescent light from the interaction of substantially all charged particle beamlets of the array of charged particle beamlets with the sample.

A scanning electron microscope includes: an electron optical column, arranged to generate electron beams and focus the electron beams on a specimen; a first detector, arranged to receive electrons generated by the electron beams acting on the specimen; and a second detector, arranged to receive photons generated by the electron beams acting on the specimen. The second detector includes a reflector and a photon detector. The reflector is in a ring shape and is arranged to cover the perimeter of the specimen. The reflector reflects the photons generated on the specimen onto the photon detector. The scanning electron microscope provided by the present disclosure can collect photons in a wide range, and the photon detector has a high reception efficiency.

Apparatuses for collection of upstream and downstream transmission electron microscopy (TEM) cathodoluminescence (CL) emitted from a sample exposed to an electron beam are described. A first fiber optic cable carries first CL light emitted from a first TEM sample surface, into a spectrograph. A second fiber optic cable carries second CL light emitted from a second TEM sample surface into the spectrograph. The first and second fiber optic cables are positioned such that the spectrograph produces a first light spectrum for the first fiber optic cable and a separate light spectrum for the second fiber optic cable. The described embodiments allow collection of TEM CL data in a manner that allows analyzing upstream and downstream TEM CL signals separately and simultaneously with an imaging spectrograph.

A method and an apparatus are provided for inspecting a sample. The apparatus includes a sample holder for holding the sample, a charged particle column for generating and focusing one or more charged particle beams at one or more charged particle beam spots onto the sample, a scanning deflector for moving the charged particle beam spot(s) over the sample, a photon detector configured for detecting photons created when the one or more charged particle beams impinge on the sample or when the one or more charged particle beams impinge onto a layer of luminescent material after transmission through the sample, an optical assembly for projecting or imaging at least part of the photons from the charged particle beam spot(s) along an optical beam path onto the photon detector, and a shifting unit for shifting the optical beam path and/or the photon detector with respect to each other.

A wafer having μLEDs is inspected using cathodoluminescence microscopes. A fast scan is enabled by splitting the CL beam into several beams and sensing the beams with point detectors. Optical filters are inserted in the optical path upstream of the detectors, such that each detector senses a different frequency band. The signals are ratioed and the ratios are compared to expected reference. Regions of extreme value are identified and, if desired, a high resolution scan is performed on the regions or a sample of the regions. Viability score is calculated for each identified region.

Systems and methods for automated alignment of cathodoluminescence (CL) optics in an electron microscope relative to a sample under inspection are described. Accurate placement of the sample and the electron beam landing position on the sample with respect to the focal point of a collection mirror that reflects CL light emitted by the sample is critical to optimizing the amount of light collected and to preserving information about the angle at which light is emitted from the sample. Systems and methods are described for alignment of the CL mirror in the XY plane, which is orthogonal to the axis of the electron beam, and for alignment of the sample with respect to the focal point of the CL mirror along the Z axis, which is coincident with the electron beam.

A scanning electron microscope is disclosed. The scanning electron microscope includes: an electron optical column, arranged to generate electron beams and focus the electron beams on a specimen; a first detector, arranged to receive electrons generated by the electron beams acting on the specimen; and a second detector, arranged to receive photons generated by the electron beams acting on the specimen. The second detector includes a reflector and a photon detector. The reflector is in a ring shape and is arranged to cover the perimeter of the specimen. The reflector reflects the photons generated on the specimen onto the photon detector. The scanning electron microscope provided by the present disclosure can collect photons in a wide range, and the photon detector has a high reception efficiency.

The invention relates to an apparatus and a method for inspecting a sample. The apparatus includes a sample holder for holding the sample, at least the sample holder comprises a cooling system which is configured for cooling at least the sample, preferably to cryogenic temperatures; a charged particle exposure system includes an assembly for projecting a focused beam of primary charged particles onto the sample held by the sample holder; and a light optical microscope. The sample holder includes a sheet of a scintillator material, and the sample holder is configured to position the sample in between the charged particle optical column and the sheet of the scintillator material. The light optical microscope includes a detection system configured for acquiring an optical image of at least a part of the sheet of the scintillator material.

The invention relates to an apparatus and a method for inspecting a sample. The apparatus includes a sample holder for holding the sample, at least the sample holder comprises a cooling system which is configured for cooling at least the sample, preferably to cryogenic temperatures; a charged particle exposure system includes an assembly for projecting a focused beam of primary charged particles onto the sample held by the sample holder; and a light optical microscope. The sample holder includes a sheet of a scintillator material, and the sample holder is configured to position the sample in between the charged particle optical column and the sheet of the scintillator material. The light optical microscope includes a detection system configured for acquiring an optical image of at least a part of the sheet of the scintillator material.

An embodiment of electron microscope system is described that comprises an electron column pole piece and a light guide assembly operatively coupled together. The light guide assembly also includes one or more detectors, and a mirror with a pressure limiting aperture through which an electron beam from an electron source passes. The mirror is also configured to reflect light, as well as to collect back scattered electrons and secondary electrons.