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The article presents a detailed characterization of the ionization process taking place inside a miniature MEMS-type ion-sorption vacuum pump, based on the Penning pump architecture. Influence of a variety of parameters on the discharge current has been investigated. These include: magnetic field, type of material used for the electrodes as well as horizontal and vertical dimensions of the micropump. It was found that the micropump works efficiently as long as the magnetic field is higher than 0.3 T, and the pumping cell's dimensions exceed 1£1£1 mm3. Best results have been obtained for copper and aluminum cathodes and low resistivity silicon anodes. [ABSTRACT FROM AUTHOR]

The concept of a miniature transmission electron microscope (TEM) on chip is presented. This idea assumes manufacturing of a silicon-glass multilayer device that contains a miniature electron gun, an electron optics column integrated with a high vacuum micropump, and a sample microchamber with a detector. In this article the field emission cathode, utilizing carbon nanotubes (CNT), and an electron optics column with Einzel lens, made of silicon, are both presented. The elements are assembled with the use of a 3D printed polymer holder and tested in a vacuum chamber. Effective emission and focusing of the electron beam have been achieved. This is the first of many elements of the miniature MEMS (Micro-Electro-Mechanical System) transmission electron microscope that must be tested before the whole working system can be manufactured. [ABSTRACT FROM AUTHOR]

Generation and maintenance of the high vacuum in the MEMS-type (micro-electromechanical system) microsystems and vacuum nanoelectronics devices remain a major problem today. The phenomena of gas desorption from the surface of a microcavity and outgassing of materials limit the vacuum to the level of about 10-1 Pa. In this paper, a new MEMS-type micropump for generating a high vacuum in a microcavity is presented. The main component of the ion-sorption micropump is a carbon nanotube (CNT) field-emission electron source. Test structures of the electron source with electrophoretically deposited CNT have been fabricated and measured. A satisfactory value of the emission current and a low turn-on voltage have been obtained. The elaborated electron source has been applied to the micropump structure; it has enabled us to achieve a vacuum level below 10-3 Pa. [ABSTRACT FROM AUTHOR]

This paper presents a field emitter in the form of a silicon tip covered with a layer of carbon nanotubes. The emitted beam is focused with a set of two electrostatic lenses and - which is novelty in such structures - with a magnetic field. The presented approach gave very promising results. The field emitter was able to provide a high emission current (about 50 µA) and a beam with a small and homogeneous spot. Such electron sources are necessary components of many miniature MEMS and nanoelectronics devices. The presented source is dedicated especially for the use in currently developed MEMS X-ray sources and MEMS electron microscopes., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)