  We present the findings of the superconductivity in the silicon
nanostructures prepared by short time diffusion of boron after preliminary
oxidation of the n-type Si (100) surface. These Si-based nanostructures
represent the p-type high mobility silicon quantum well (Si-QW) confined by the
delta - barriers heavily doped with boron. The ESR studies show that the delta
- barriers appear to consist of the trigonal dipole centers, B(+)-B(-), which
are caused by the negative-U reconstruction of the shallow boron acceptors,
2B(0)=>B(+)-B(-). The temperature and magnetic field dependencies of the
resistance, thermo-emf, specific heat and magnetic susceptibility demonstrate
that the high temperature superconductivity observed seems to result from the
transfer of the small hole bipolarons through these negative-U dipole centers
of boron at the Si-QW - delta - barrier interfaces. The value of the
superconductor energy gap obtained is in a good agreement with the data derived
from the oscillations of the conductance in normal state and of the
zero-resistance supercurrent in superconductor state as a function of the bias
voltage. These oscillations appear to be correlated by on- and off-resonance
tuning the two-dimensional subbands of holes with the Fermi energy in the
superconductor delta - barriers. Finally, the proximity effect in the S- Si-QW
-S structure is revealed by the findings of the multiple Andreev reflection
(MAR) processes and the quantization of the supercurrent.
