  The symmetric part of the distribution of the electrons in a semiconductor
submicron film, placed between a heater and refrigeration unit, is derived and
analyzed. It is shown that, in general, it is of non-Fermi (non-Maxwellian)
nature. A new mechanism is proposed to account for the non-Maxwellian form of
the symmetric part of the distribution function. This mechanism is based on the
different energy dependences of the momentum relaxation time in the bulk of the
semiconductor and its skin layer.
