Vol 47, No 4 (2018)

In the study, a technique for formation of planar microheaters that make it possible to heat an active zone to a temperature higher than 500°С is proposed and successfully implemented. The developed heating elements are distinguished by low power consumption, short response time, and extremely high resistance to impact loads. The synthetic approaches used in the work (anodic oxidation, photolithography, and magnetron sputtering) feature manufacturability and scaling simplicity. This makes planar heating elements a promising platform based on which semiconductor and thermocatalytic sensors of toxic and explosive gases may be created.

The effect of the CF₄/C₄F₈ ratio in a CF₄ + C₄F₈ + Ar mixture on the parameters of the gaseous phase of a low-pressure inductively coupled plasma, defining the kinetics and selectivity of etching in an SiO₂/Si system, is investigated. It is found that increasing the SiO₂/Si etching ratio, with an increase of the quantity of C₄F₈ in the plasma-forming mixture, is determined by various changes of the effective interaction probabilities for these materials. It is demonstrated that, within the investigated range of conditions, the kinetics of the formation of the fluorocarbon polymer film on the processed surface exerts a decisive influence on the character of the variation of the effective interaction probability. The interrelationships between the gas-phase and heterogeneous characteristics of the etching process are revealed.

The problems of modeling the basic electrophysical characteristics of asymmetrically doped double- gate SOI CMOS nanotransistors are discussed. A mathematical model for the distribution of the potential of the working region, which follows from the analytic solution of the 2D Poisson equation is treated. The variant of the asymmetric channel (counting from the source) with highly doped and low-doped regions is analyzed. The results of the model calculations of the potential distribution of sub-50-nm structures are in good agreement with the simulation data obtained using a commercially available ATLAS^TM software package intended for modeling 2D transistor structures. Based on the obtained potential distributions, the current–voltage performances are calculated using the model of current formulated within the charge separation concept, taking into account the modified expression for the saturation rate. For the topological norms chosen, the optimization of the parameters of an asymmetrically doped profile provides an additional opportunity to monitor the key characteristics along with the thicknesses of the working region and the gate oxide, which is important in analyzing the applicability of nanotransistor structures, in particular, for analog applications.

The correlated regularities of the variations in the structural and phase composition and morphological and field-emission characteristics of the surface-structured р- and n-Si crystals upon stepwise highdose ion-beam carbon processing are studied. It is shown that the stepwise high-dose ion implantation of carbon atoms into the surface of silicon wafers structured using nonlithographic carbon mask coatings makes it possible to reduce field-emission thresholds and increase the densities of the maximum field-emission currents by more than two orders of magnitude relative to the values for emitter arrays fabricated using traditional microelectronic technologies. The physicochemical mechanisms responsible for modifying the surface properties of silicon structures upon carbon ion implantation are discussed.