Incoherent mesoscopic phenomena in semiconductor structure of macroscopic size

In Si : B MOS-structures (NB = 1.2 × 1018 cm−3), the formation of quasi-2D channel of hopping conductivity occurs in the region, where Fermi energy crosses the impurity band, shifted by gate voltage Vg. Rising gate voltage above zero (Vg > 0, the case of depletion) results in reproducible fluctuations of transverse voltage Vy between Hall probes, at temperatures 4.2–30 K and magnetic fields B up to 1 T, in spite of the macroscopic size of the sample (150 x 50 μm2) and the potential probe ledges (15 x 5 μm2).