Rashba Interaction in Polysilicon Layers SemOI-Structures

Abstract

The measurements of the magnetoresistance for p-type poly-Si with concentration 2.4 × 10¹⁸ cm⁻³ were carried out in the low temperature range 4.2–20 K and in the magnetic field up to 14 T. The results showed the presence of a negative magnetoresistance in polycrystalline silicon films in SemOI-structures. The low-temperature transport of charge carriers in p-type polycrystalline silicon films was considered within the framework of hopping conductivity and can be described by the spin–orbital interaction in the theory of weak localization. The calculated values of the coherence phase length 3–4 nm and the spin–orbit coherence length 30–50 nm at low temperatures 4.2–30 K correlate with parameters of hopping conductance and grain size, respectively, which show a contribution of Rashba spin–orbit interaction with energy Δ_SO = 1.6 meV in the conductance not only inside the grains, but also its surface and between grain boundaries of polycrystalline silicon in SemOI structures.