The paper analyzes the features of a liquid zones thermomigration process in a crystal for the formation of semiconductor materials with the required substructure, carried out in comparison with a diffusion method. The primary factors defining and accompanying the thermomigration process of liquid inclusion in a crystal are considered. The geometrical, concentration, temperature-time and other conditions at which the choice of the thermomigration effect as a local doping method is preferable are revealed and described. It is shown, that the thermomigration method possesses considerable advantages, in particular, the possibilities of decreasing doping process temperature, increasing process speed, increasing the distribution uniformity of the doping impurity and improves the crystal perfection of the doped layers. The quantitative estimations related to the revealed conditions, are illustrated with an aluminium-silicon example.