We measured the low temperature subgap resistance of titanium nitride
(superconductor, Tc=4.6K)/highly doped silicon (degenerated semiconductor) SIN
junctions, where I stands for the Schottky barrier. At low energies, the subgap
conductance is enhanced due to coherent backscattering of the electrons towards
the interface by disorder in the silicon (''reflectionless tunneling''). This
Zero Bias Anomaly (ZBA) is destroyed by the temperature or the magnetic field
above 250mK or 0.04T respectively. The overall differential resistance behavior
(vs temperature and voltage) is compared to existing theories and values for
the depairing rate and the barrier transmittance are extracted. Such an
analysis leads us to introduce an effective temperature for the electrons and
to discuss heat dissipation through the SIN interface.Comment: 23 pages, 6 figures, added references and minor corrections. Accepted
to Journal of Low Temperature Physic