An electron beam system for wafer inspection and review of 3D devices provides a depth of focus up to 20 microns. To inspect and review wafer surfaces or sub-micron-below surface defects with low landing energies in hundreds to thousands of electron Volts, a Wien-filter-free beam splitting optics with three magnetic deflectors can be used with an energy-boosting upper Wehnelt electrode to reduce spherical and chromatic aberration coefficients of the objective lens.

A multi-beam apparatus for observing a sample with high resolution and high throughput is proposed. In the apparatus, a source-conversion unit changes a single electron source into a virtual multi-source array, a primary projection imaging system projects the array to form plural probe spots on the sample, and a condenser lens adjusts the currents of the plural probe spots. In the source-conversion unit, the image-forming means is on the upstream of the beamlet-limit means, and thereby generating less scattered electrons. The image-forming means not only forms the virtual multi-source array, but also compensates the off-axis aberrations of the plurality of probe spots.

A charged-particle source for generating a charged-particle comprises a sequence of electrodes, including an emitter electrode with an emitter surface, a counter electrode held at an electrostatic voltage with respect to the emitter electrode at a sign opposite to that of the electrically charged particles, and one or more adjustment electrodes surrounding the source space between the emitter electrode and the counter electrode. These electrodes have a basic overall rotational symmetry along a central axis, with the exception of one or more steering electrodes which is an electrode which interrupts the radial axial-symmetry of the electric potential of the source, for instance tilted or shifted to an eccentric position or orientation, configured to force unintended, secondary charged particles away from the emission surface.

A charged-particle source for generating a charged-particle comprises a sequence of electrodes, including an emitter electrode with an emitter surface, a counter electrode held at an electrostatic voltage with respect to the emitter electrode at a sign opposite to that of the electrically charged particles, and one or more adjustment electrodes surrounding the source space between the emitter electrode and the counter electrode. These electrodes have a basic overall rotational symmetry along a central axis, with the exception of one or more steering electrodes which is an electrode which interrupts the radial axial-symmetry of the electric potential of the source, for instance tilted or shifted to an eccentric position or orientation, configured to force unintended, secondary charged particles away from the emission surface.

A charged particle multi-beam device includes a charged particle source, a collimator lens, a multi-light-source forming unit, and a reduction projection optical system. The multi-light-source forming unit has first to third porous electrodes disposed side by side in an optical axis direction. A plurality of holes for causing the multi-beams to pass is formed in each of the first to third porous electrodes. The first porous electrode and the third porous electrode have the same potential and the second porous electrode has potential different from the potential of the first porous electrode and the third porous electrode. A diameter of the holes on the second porous electrode is formed larger further away from an optical axis such that a surface on which the multi-light sources are located is formed in a shape convex to the charged particle source side.

A charged particle multi-beam device includes a charged particle source, a collimator lens, a multi-light-source forming unit, and a reduction projection optical system. The multi-light-source forming unit has first to third porous electrodes disposed side by side in an optical axis direction. A plurality of holes for causing the multi-beams to pass is formed in each of the first to third porous electrodes. The first porous electrode and the third porous electrode have the same potential and the second porous electrode has potential different from the potential of the first porous electrode and the third porous electrode. A diameter of the holes on the second porous electrode is formed larger further away from an optical axis such that a surface on which the multi-light sources are located is formed in a shape convex to the charged particle source side.

The purpose of the present invention is to provide an emitter capable of easily and highly efficiently emitting electrons, an electron gun using same, and an electronic device.

This emitter is provided with a cathode holder, and an acicular substance secured to the cathode holder. An end, to which the acicular substance is secured, of the cathode holder is bent at α(α(°) satisfies 5<α≤70) that is an angle formed with respect to a cathode axis being the longitudinal direction of the cathode holder, the acicular substance is a single crystal nanowire or nanotube, and a relation L/T between the thickness T ( μm) of the end of the cathode holder and a length L ( μm) by which the acicular substance protrudes from the end satisfies 0.3≤L/T≤2.5.

The purpose of the present invention is to provide an emitter capable of easily and highly efficiently emitting electrons, an electron gun using same, and an electronic device.

This emitter is provided with a cathode holder, and an acicular substance secured to the cathode holder. An end, to which the acicular substance is secured, of the cathode holder is bent at α(α(°) satisfies 5<α≤70) that is an angle formed with respect to a cathode axis being the longitudinal direction of the cathode holder, the acicular substance is a single crystal nanowire or nanotube, and a relation L/T between the thickness T ( μm) of the end of the cathode holder and a length L ( μm) by which the acicular substance protrudes from the end satisfies 0.3≤L/T≤2.5.

A Schottky thermal field emitter (TFE) source integrated with a beam splitter by a standoff, which supports the beam splitter above the Schottky TFE extractor faceplate by a distance of 0.05 mm to 2 mm. The beam splitter includes a microhole array integrated with the standoff and being disposed opposite the extractor faceplate, the microhole array having a plurality of microholes that split the electron beam generated by the Schottky TFE into a plurality of beamlets. The support and extractor may be fabricated from the same material or from different materials. The support may be formed from a high temperature resistive material, which causes a potential difference between the extractor and the microhole array. This potential difference creates positively charged electrostatic lenses at the microholes, which increases current in the individual beamlets. Voltage on the microarray plate may be varied to achieve a high beamlet current.

A Schottky thermal field emitter (TFE) source integrated with a beam splitter by a standoff, which supports the beam splitter above the Schottky TFE extractor faceplate by a distance of 0.05 mm to 2 mm. The beam splitter includes a microhole array integrated with the standoff and being disposed opposite the extractor faceplate, the microhole array having a plurality of microholes that split the electron beam generated by the Schottky TFE into a plurality of beamlets. The support and extractor may be fabricated from the same material or from different materials. The support may be formed from a high temperature resistive material, which causes a potential difference between the extractor and the microhole array. This potential difference creates positively charged electrostatic lenses at the microholes, which increases current in the individual beamlets. Voltage on the microarray plate may be varied to achieve a high beamlet current.