arXiv subjects

Daria V. Beznasyuk

Publications and source records attributed to Daria V. Beznasyuk.

4 recordsLinked to original sources

arXiv2025

Cryogenic performance of field-effect transistors and amplifiers based on selective area grown InAs nanowires

Indium-Arsenide (InAs) nanowire field-effect transistors (NWFETs) are promising platforms for high-speed, low-power nanoelectronics operating at cryogenic conditions, relevant for quantum information processing. We use selective area growth (SAG) of nanowires to realize scalable and planar nanowire device geometries that are compatible with standard semiconductor processing techniques. NWFETs are fabricated and their low temperature characteristics - including ION/IOFF ratios, threshold voltages, sub-threshold slope, interfacial trap density, hysteresis, and mobility - are characterized. The NWFETs operate effectively in integrated circuitry relying on saturation-mode operation. In sub-threshold applications such as amplifiers, we find bandwidths exceeding our cryostat wiring, but the gate hysteresis presents challenges for precise tuning of the amplifier operating point. We discuss the role of crystal imperfections and fabrication processes on the transistor characteristics and propose strategies for further improvements.

cond-mat.mes-hall↗

arXiv2024

Statistical Reproducibility of Selective Area Grown InAs Nanowire Devices

New approaches such as selective area growth, where crystal growth is lithographically controlled, allow the integration of bottom-up grown semiconductor nanomaterials in large-scale classical and quantum nanoelectronics. This calls for assessment and optimization of the reproducibility between individual components. We quantify the structural and electronic statistical reproducibility within large arrays of nominally identical selective area growth InAs nanowires. The distribution of structural parameters is acquired through comprehensive atomic force microscopy studies and transmission electron microscopy. These are compared to the statistical distributions of the cryogenic electrical properties of 256 individual SAG nanowire field effect transistors addressed using cryogenic multiplexer circuits. Correlating measurements between successive thermal cycles allows distinguishing between the contributions of surface impurity scattering and fixed structural properties to device reproducibility. The results confirm the potential of SAG nanomaterials, and the methodologies for quantifying statistical metrics are essential for further optimization of reproducibility.

physics.app-ph↗

arXiv2022

Doubling the mobility of InAs/InGaAs selective area grown nanowires

Selective area growth (SAG) of nanowires and networks promise a route toward scalable electronics, photonics and quantum devices based on III-V semiconductor materials. The potential of high-mobility SAG nanowires however is not yet fully realized, since interfacial roughness, misfit dislocations at the nanowire/substrate interface and non-uniform composition due to material intermixing all scatter electrons. Here, we explore SAG of highly lattice-mismatched InAs nanowires on insulating GaAs(001) substrates and address these key challenges. Atomically smooth nanowire/substrate interfaces are achieved with the use of atomic hydrogen (a-H) as an alternative to conventional thermal annealing for the native oxide removal. The problem of high lattice mismatch is addressed through an In$_x$Ga$_{1-x}$As buffer layer introduced between the InAs transport channel and the GaAs substrate. The Ga-In material intermixing observed in both the buffer layer and the channel is inhibited via careful tuning of the growth temperature. Performing scanning transmission electron microscopy and x-ray diffraction analysis along with low-temperature transport measurements we show that optimized In-rich buffer layers promote high quality InAs transport channels with the field-effect electron mobility over~10000~cm$^2$V$^{-1}$s$^{-1}$. This is twice as high as for non-optimized samples and among the highest reported for InAs selective area grown nanostructures.

cond-mat.mtrl-sci↗

arXiv2017

Dislocation-free axial InAs-on-GaAs nanowires on silicon

We report on the growth of axial InAs-on-GaAs nanowire heterostructures on silicon by molecular beam epitaxy using 20 nm diameter Au catalysts. First, the growth parameters of the GaAs nanowire segment were optimized to achieve a pure wurtzite crystal structure. Then, we developed a two-step growth procedure to enhance the yield of vertical InAs-on-GaAs nanowires. We achieved 90% of straight InAs-on-GaAs nanowires by further optimizing the growth parameters. We investigated the composition change at the interface by energy dispersive X-ray spectroscopy and the nanowire crystal structure by transmission electron microscopy. The nominal composition of the InAs segment is found to be In$_{x}$Ga$_{1-x}$As with $x$=0.85 and corresponds to 6% of lattice mismatch with GaAs. Strain mapping performed by the geometrical phase analysis of high-resolution images revealed a dislocation-free GaAs/InAs interface. In conclusion, we successfully fabricated highly mismatched heterostructures, confirming the prediction that axial GaAs/InAs interfaces are pseudomorphic in nanowires below 40 nm diameter.

cond-mat.mtrl-sci↗