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Information × Registration Number 0213U001399, 0110U006288 , R & D reports Title Researrch and development of regular arrays of silicon nanowires in dielectric matrix and resonant-tunneling structures. popup.stage_title Head Evtukh Anatoli Antonovych, Registration Date 01-02-2013 Organization Institute of Semiconductor Physics of National Academy of Sciences of Ukrain popup.description2 Report is submitted in one volume and has 41 pages, including graphics 17, tables 2, used sources 33. Keywords: electron field emission, silicon nanowires, technology, gas transport reactions, porous oxide matrix, work function. The purpose of the phase: to develop technologies and investigate the physical processes at the formation of Al2O3 dielectric matrix and growth of Si nanowires in them. The formation technology of the porous alumina matrix by electrochemical oxidation of aluminum has been developed and further development of the technology for growth of silicon nanowires has been performed. The characteristics of growth of the ensemble of silicon nanowires at epitaxy by chemical vapor deposition in open flowing and closed bromide systems for their applications in nanoelectronic devices, such as field emission cathodes have been studied. The dependence of pore diameter and the distance between the pores on the composition of the solution and voltage during the formation of porous aluminum oxide matrix by electrochemical oxidation of aluminum has been determined. It is shown that this method allows to obtain a matrix with pore diameters in the range of 5-130 nm. The conditions of porous oxide matrix formation have been optimized. It was shown that the reproducible obtaining of dielectric matrix of the aluminum oxide with a small spread of the diameter and the distance between the pores can be realized by the use of multistage process. The first stage of anodic oxidation is carried out in 0.3 M solution of oxalic acid at a voltage of 40 V, a temperature of 0 ° C and for 2 h. Then all porous aluminum oxide layer is removed by acid mixture of 0.2 M H2CrO4 and 0,4 M H3PO4 at 60 ° C for 5 min. Then again anodization process is performed. And so until the sharp decline in current. As the result pore size of 25 nm has been obtained. Most orderliness is achieved at a voltage of about 40 V, it is improved with increasing the time of the first anodizing process and acid concentration. At the film thickness of 2mkm the anodization time was 15 min. As a result, a series of experiments in open hydrogen flowing and closed bromide systems the ensembles of Si NCs with an average diameter of 100 nm have been obtained. It is shown that the average diameter of the nanocrystals depends on the diameter of coagulated nanodrops of Si-Au, and the diameter of the latter depends on the thickness of the deposited gold film, thus the increasing of the growth time leads to an increase in the diameter of nanowires. The modeling of the kinetics of the growing process makes it possible to predict the geometric dimensions of the crystals, based on the main parameters of the process. Based on the modeling of axial growth of silicon whiskers by chemical vapor deposition in a closed system ther critical diameter of nanocrystals (45 nm) has been defined. It is limited by supersaturation in the system. It is shown that the rate of radial growth of nanoscale NCs of the smallest diameter is too small and does not depend on the diameter, while larger diameter crystals undergo substantial thickening by vapor-crystal mechanism. It allows to predict the geometric dimensions of the core and shell of the crystal to create the radial heterostructures suitable for electronic applications. Product Description popup.authors Євтух Анатолій Антонович Кизяк Анатолій Юрійович Лісовський Ігор Петрович Литовченко Володимир Григорович popup.nrat_date 2020-04-02 Close