Electron-Beam Synthesis of Dielectric Coatings Using Forevacuum Plasma Electron Sources (Review)

This is a review of current developments in the field of ion-plasma and beam methods of synthesis of protective and functional dielectric coatings. We give rationales for attractiveness and prospects of creating such coatings by electron-beam heating and following evaporation of dielectric targets. Forevacuum plasma electron sources, operating at elevated pressure values from units to hundreds of pascals, make it possible to exert the direct action of an electron beam on low-conductive materials. Electron-beam evaporation of aluminum oxide, boron, and silicon carbide targets is used to exemplify the particular features of electron-beam synthesis of such coatings and their parameters and characteristics.

Calculation of single-layer dielectric coatings for antireflection in a given range of angles of incidence

In this work, the problem of antireflection a single-layer magneto-dielectric system is formulated when a plane electromagnetic wave passes through it in the range of angles of incidence, and necessary and sufficient conditions for the existence of solutions to this problem are obtained

Influence of additional dielectric coatings on the electrode surfaces on selected parameters of acoustic emission signals in high-voltage gas insulation systems

The paper is devoted to the study of impact of additional dielectric coatings placed on the surface of the electrodes on the operation of a high-voltage insulation system with air as insulating medium. The study mainly focused on measurement of partial discharges (PDs) with the use of acoustic emission method. Tests were conducted in various levels of chamber pressure. Applicable parameters of recorded signals were analyzed with the use of applications developed in the environment of MATLAB software. The results of analyses clearly show that presence of additional coatings has impact on signal parameters and thus indirectly on PDs. The use of coatings reduces the duration of a single pulse (event) and increases its amplitude. Furthermore, the influence of degradation of the coating caused by individual discharges on the values of the analyzed parameters was analyzed. The study has shown, however, that this effect is negligible.

Electron-beam deposition of thermoconducting ceramic coatings for microelectronic devices

This paper presents the experimental study of dielectric coatings based on aluminum oxide (Al2O3) and aluminum nitride (AlN) ceramics as applied to their use in microelectronics. It is shown that the coatings obtained by electron-beam evaporation of ceramic in forevacuum pressures (1-100 Pa) endow devices with required dielectric parameters and improves heat sink from the surface of monolithic integral circuits.

Контроль диэлектрической проницаемости и толщины анизотропных диэлектрических покрытий методом поверхностных электромагнитных волн

The widespread use of anisotropic composite dielectric coatings operating in the microwave range in various science-intensive areas has led to the search and selection of effective methods of radio wave nondestructive testing of their electrophysical parameters. The existing approaches based on the estimation of the reflection and transmission coefficients of electromagnetic waves have low accuracy and reliability of estimating the components of the complex permittivity tensor and the thickness of such coatings, do not take into account their frequency dispersion and placement on a metal base. We present the new method of local measurements of components of the complex permittivity tensor with allowance for their frequency dispersion and a thickness anisotropic dielectric coatings with radial surface microwaves. The method is based on the solution of inverse problem in the determination of components of the complex permittivity tensor and a thickness coatings from the frequency and angular dependence of the attenuation coefficient of the field of a radial surface electromagnetic wave excited in a test sample. A numerical and experimental study show that for a measurement bandwidth of 9–13,5 GHz the errors in estimating the anisotropy coefficients do not exceed 10% with a confidence coefficient of 0.95. We introduce and substantiate a statistical limit of the resolution of the anisotropy of permittivity; this makes it possible to evaluate the possibility of discriminating between two close values any pair of components of the permittivity tensor. Numerical and field experiments have shown that the method can provide their assessment with a difference of 0.2–0.3% or less in the frequency band of 9–13.5 GHz.

Nano-imprinted subwavelength gratings as polarizing beamsplitters

Polarizing beamsplitters have numerous applications in optical systems, such as systems for freeform surface metrology. They are classically manufactured from birefringent materials or with stacks of dielectric coatings. We present a binary subwavelength-structured form-birefringent diffraction grating, which acts as a polarizing beamsplitter for a wide range of incidence angles −30∘…+30∘. We refine the general design method for such hybrid gratings. We furthermore demonstrate the manufacturing steps with Soft-UV-Nanoimprint-Lithography, as well as the experimental verification, that the structure reliably acts as a polarizing beamsplitter. The experimental results show a contrast in efficiency for TE- and TM-polarization of up to 1:18 in the first order, and 34:1 in the zeroth order. The grating potentially enables us to realize integrated compact optical measurement systems, such as common-path interferometers.