LAUSR

In this paper, we propose a new method for double sided diffusion of lithium ions into a monocrystalline silicon wafer for the further fabrication of Si (Li) p-i-n nuclear radiation detectors with a diameter of the sensitive surface of more than 110 mm and a thickness of the sensitive region of more than 4 mm. It was found that the optimal regime for lithium diffusion into large-diameter silicon is at a temperature of T  (450  20) C, time t  3 min, thickness hLi  (300  10) mm. The theoretical assumptions and experimental characteristics of double sided diffusion are considered. As initial material the dislocation free monocrystalline cylindrical silicon crystal of the p-type, obtained by the floating-zone method (with a diameter 110 mm, thickness 8-10 mm, resistivity   1000 ÷ 10000 Ohm·cm and life time τ  500 s) and the silicon crystal of the p-type (with a diameter of 110 mm, resistivity   10 ÷ 12 Ohm·cm, lifetime τ  50 s, grown in an argon atmosphere) obtained by the Czochralski method were used. Correspondingly, the technological processes of mechanical and chemical processing of semiconductor wafers based on silicon of a large area have been improved.