Patent Number: 040424545
Section: claims

1. A method of producing a homogeneously n-doped Si rod having a specific resistivity greater than 30 ohm .times. cm wherein a Si rod is subjected to radiation by thermal neutrons and a nuclear reaction occurs within such rod in accordance with: EQU Si.sup.30 (n, .gamma.) Si.sup.31 .sup..beta..sup.- P.sup.31 subjecting a polycrystalline Si rod having a specific resistivity of 550 ohm .times. cm, n-type to at least one crucible-free zone melting process in a suitably protective environment so as to free said rod of any donor material present therein;  converting the so-attained polycrystalline rod into a monocrystalline state in a conventional manner;  measuring the specific resistivity of the so-produced monocrystalline rod; and  subjecting said monocrystalline rod to controlled radiation by thermal neutrons in accordance with the measured resistivity, the intensity of such controlled radiation comprising 8 .times. 10.sup.13 neutrons/cm.sup.2 .times. sec. and the radiation duration comprising about one hour whereby an n-doped Si rod having a concentration of about 4 .times. 10.sup.13 atoms of phosphorous/cm.sup.3 of silicon therein is produced.