The results of magnetoconductivity measurements in GaInAs quantum wells are presented. The observed magnetoconductivity appears due to the quantum interference, which lead to the weak localization effect. It is established that the details of the weak localization are controlled by the spin splitting of electron spectra. A theory is developed which takes into account both linear and cubic in electron wave vector terms in spin splitting, which arise due to the lack of inversion center in the crystal, as well as the linear terms which appear when the well itself is asymmetric. It is established that, unlike spin relaxation rate, contributions of different terms into magnetoconductivity are not additive. It is demonstrated that in the interval of electron densities under investigation ((0.98 − 1.85)·1012 cm −2 ) all three contribution are comparable and have to be taken into account to achieve a good agreement between the theory and experiment. The results obtained from comparison of the experiment and the theory have allowed us to determine what mechanisms dominate the spin relaxation in quantum wells and to improve the accuracy of determination of spin splitting parameters in A3B5 crystals and 2D structures. 73.20.Fz,73.70.Jt,71.20.Ej,72.20.My

Abstract. SiC nanowires are of high interest since they combine the physical properties of SiC with those induced by their low dimensionality. For this reason, a large number of scientific studies have been dedicated to their fabrication and characterization as well as to their application in devices. SiC nanowires growth involving different growth mechanisms and configurations was the main theme for the large majority of these studies. Various physical characterization methods have been employed for evaluating SiC nanowire quality. Very low diameter (<10 nm) nanowires as well as nanowires free of planar defects have not been demonstrated and these are some of the main challenges. Another issue is the high unintentional doping of the nanowires that does not allow the demonstration of high performance field effect transistors using SiC nanowires as channel material. On the other hand, the grown nanowires are suitable for field emission applications and to be used as reinforcing material in composite structures as well as for increasing the hydrophobicity of Si surfaces. All these aspects are examined in detail in the different sections of the present paper.

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We have successfully demonstrated p-type silicon nanowire field-effect transistors (Si NW p-FETs) prepared using B-ion implantation with a dose of 1 × 10 13 ions/cm 2 and an energy of 10 keV. The experimental I D -V DS characteristics for B-implanted Si NW FETs revealed a clear p-channel FET behavior with a hole mobility of ∼6.9 cm 2 /(V · s), a hole concentration of ∼1.1 × 10 19 cm -3 , and a transconductance of ∼29 nS/µm at a V DS of 0.1V. The B-implanted Si NWs were annealed at a temperature of 950°C for 30 and 60 s. The 2D-ATHENA and ATLAS software were used to accurately simulate the device fabrication process and the electrical performance, respectively.

Deep electron traps in heteroepitaxial β-SiC films grown on Si(100) substrates by chemical vapor deposition were investigated. Capacitance deep level transient spectroscopy revealed the presence of several traps, the majority of which are rather process-induced as expected for a highly defective material such as β-SiC grown heteroepitaxially on Si. Samples of different origin as well as various surface treatments have been used to determine traps intrinsic to β-SiC heteroepitaxial material. Three main traps were detected, independently of the surface treatment, at 0.32, 0.52, and 0.56 eV below the conduction-band minimum. Comparison with theoretically predicted activation energies for the single native defects did not permit the assignment of the observed traps to any of these defects.

We present numerical simulations of gate-all-around (GAA) 3C-SiC and Si nanowire (NW) field effect transistors (FETs) using a full quantum self-consistent Poisson-Schrödinger algorithm within the non-equilibrium Green's function (NEGF) formalism. A direct comparison between Si and 3C-SiC device performances sheds some light on the different transport properties of the two materials. Effective mobility extraction has been performed in a linear transport regime and both phonon- (PH) and surface-roughness-(SR) limited mobility values were computed. 3C-SiC FETs present stronger acoustic phonon scattering, due to a larger deformation potential, resulting in lower phonon-limited mobility values. Although Si NW devices reveal a slightly better electrostatic control compared to 3C-SiC ones, SR-limited mobility shows a slower degradation with increasing charge density for 3C-SiC devices. This implies that the difference between Si and 3C-SiC device mobility is reduced at large gate voltages. 3C-SiC nanowires, besides their advantages compared to silicon ones, present electrical transport properties that are comparable to the Si case.

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