METHOD FOR PRODUCING N-TYPE NUCLEAR-DOPED SILICON (OPTIONS) Russian patent published in 2000 - IPC

FIELD: electronic engineering. SUBSTANCE: method involves enrichment of source silicon ingot with N-times stable isotope ³⁰Si and its irradiation with neutrons. According to main nuclear reaction (n, γ), desired concentration of donor ³⁰Si is obtained on stable isotope ³¹P contained in natural mixture of silicon isotopes. Then ingot is decontaminated, subjected to radiometric check-up and to high-temperature annealing for eliminating essential portion of radiation defects and for stabilizing electrophysical properties of material. According to first option, fluence rating of neutrons is reduced N times thereby reducing concentration of radiation defects to the same degree. According to second option, fluence rating specified for irradiating silicon with natural isotope mixture is maintained, N times higher concentration of donor ³¹P and, hence, concentration of charge carriers, is obtained. For reducing amount of complex radiation defects that cannot be eliminated by post-irradiation high- temperature annealing when using second method, proportion of high-energy neutrons is reduced by means of neutron spectrum moderator. EFFECT: reduced amount of complex radiation defects and improved electrophysical properties of silicon. 2 cl, 1 dwg