arXiv subjects

Alexander Mumlyakov

Publications and source records attributed to Alexander Mumlyakov.

3 recordsLinked to original sources

arXiv2026

Superconducting properties of Nb$_{0.85}$Sc$_{0.15}$ film deposited by magnetron co-sputtering

The technology has been developed for synthesizing Nb$_{1-x}$Sc$_x$ films using magnetron co-sputtering from Nb and Sc targets. The material synthesis was accompanied by structural characterization using X-ray diffraction and X-ray reflectometry methods, which enabled the determination of thickness, phase composition and crystal structure. We also analyzed the superconducting properties. The critical temperature $T_c$ was measured for samples with different concentarions of Sc and Nb. The maximum value of $T_c$ equal to 6.35 K was observed for sample with a scandium content of approximately 15 %, which was determined by Auger spectroscopy. Transport and magnetoresistive measurements were performed in microbridges with length of 50 $\mu$m, width of 2 $\mu$m, and thickness of 30 nm. The critical current density was as high as 2.5 $\text{ MA/cm}^{2}$. Magnetic measurements were performed with the field oriented perpendicular to the sample. The upper critical field $H_{c2}(0) = 3.2$ T, electron diffusion coefficient $D = 1.1$ $\text{cm}^{2}/s$, and coherence length $\xi_{GL} = 10.1$ nm. The synthesized Nb$_{1-x}$Sc$_x$ intermetallic compound shows promise for various functional cryogenic electronics devices. \keywords{NbSc; superconductor; microbridge}

cond-mat.supr-con↗

arXiv2023

Superconducting TSV contact for cryoelectronic devices

This work focuses on the fabrication of niobium through silicon vias (TSV) superconductors interconnects. The effect of supercycle of sequential oxidation and chemical etching process on the through-etch wall quality was investigated. It was experimentally shown that the use of supercycle in the fabrication process leads to significant improvement of the TSV wall quality and removal of the defect type - scallops. After 12 times repetitions of supercycles a dissipative bonding of superconducting strips on the front and back side of the sample is observed. The critical current density of such coupling is 5x104 A/cm2. The critical ratio of substrate thickness to hole diameter at which electrical coupling is formed is 3 : 1.

cond-mat.supr-con↗

arXiv2022

Wet Scandium Etching for hard mask formation on a silicon substrate

Nowadays, microelectronics and nanoelectronics require the search for new materials, including masks for creating structures. Today, the intermediate hard mask strategy is one of the key issues in achieving a good balance between lithography and etching at the microelectronic fabrication. One of the interesting challenges in microelectronics and photovoltaics is the creation of interspacing, vertically oriented silicon arrays on Si substrate for semiconductor devices with multi-function. The fabrication of such structures is still a serious technological problem and requires searching for new approaches and materials. In this work, we propose using scandium as a new hard mask material over silicon due to its high resistance to plasma chemical etching and low sputtering coefficient. We have shown that a wet etching of the scandium layer with a thickness of several nanometers can be used to obtain pattern structures with a resolution of up to 4 microns, which is a good result for the wet etching approach. Scandium metal was found to be an excellent resistant mask over silicon under the selected plasma etching conditions. Therefore, a scandium hard mask can open up new possibilities for the formation of different microscale topographical patterns.

physics.app-ph↗