Electrically active centers formed in silicon during the high-temperature diffusion of boron and aluminum

The parameters of electrically active centers formed during the high-temperature diffusion of boron and aluminum into silicon in various media are studied by the Hall method and capacitance spectroscopy. It is found that the variation in the resistivity of the n base of the structures with p-n junctions fabricated in the study is controlled by the formation of three donor levels $Q1$, $E4$, and $Q3$ with the energies $E_c$ – 0.31, $E_c$ – 0.27, and $E_c$ – 0.16 eV. Diffusion in a chlorine-containing atmosphere introduces only a single level $E4$, but its concentration is 2.5 times lower, compared with diffusion in air. The values of the ionization energy of the $Q3$ level, measured under equilibrium (Hall effect) and nonequilibrium (capacitance spectroscopy) conditions, almost coincide. The deepest level $E1$ with an energy of $E_c$ – 0.54 eV, formed upon diffusion in both media, has no effect on the resistivity in the $n$ base of the structures.