D. А. ZATSEPIN, A. S. SIGOV, E. Z. KURMAEV

The silicon-based materials of semiconducting and insulating type are considered to be most promising for technical applications as they allow varying purposefully an electrical and thermal conductivity, microhardness, the quantum yield of luminescence, chemical reactivity and etc. by means of introducing the impurity atoms into the lattice, including transition metals. The greatest efficiency from this point of view has a method of ion implantation, which has no restrictions on the solubility limit of an element that has been introduced, provides the high controllability of the impurities distribution within the bulk of material-target at a relatively weak effect of thermodynamic constraints on the implementation process, and, finally, combines the simultaneous formation of an ion and defect complexes in a single implantation cycle. The latter opens up an additional application area for an ion implantation method, the so-called "defects engineering". The advantages of the ion implantation method demonstrate its powerful capabilities and indicate the possibility of the successful adaptation to the technology of nanoelectronics in order to create nanocomposite materials with a special combination of physical and chemical properties. In the current part of our review the physical principles and mechanisms that govern the behavior of electrons in semiconducting and insulating structures with a low- dimensionality are analyzed and discussed, their relationship with the function of electronic density of states and the quantization energy of electrons in potential wells of various types are noted and, finally, the spatial classification of semiconductor structures with a reduced dimensionality is performed.