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Publications (3)2.36 Total impact

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    ABSTRACT: DMILL bipolar transistors (npn) were exposed to 24 GeV protons and fast and thermal neutrons to fluences up to 6·10<sup>14</sup> n/cm<sup>2</sup>. Transistor common emitter current gain (β=I<sub>collector</sub>/I<sub>base</sub>) was measured after irradiations. It was found that β degradation scales as Δ(1/β)=k<sub>T</sub>·Φ<sub>T</sub> where Φ<sub>T</sub> is the fluence of thermal neutrons and as Δ(1/β)=k<sub>eq</sub>·Φ<sub>eq</sub>, with Φ<sub>eq</sub> 1-MeV equivalent fluence, if transistors are irradiated with protons or fast neutrons. Large damage factor k<sub>T</sub>∼3·k<sub>eq</sub> was measured. Thermal neutrons do not have sufficient energy to displace a Si atom. Their damage mechanism is, therefore, identified with <sup>10</sup>B(n,α)<sup>7</sup>Li reaction from which energetic α and Li particles produce bulk damage in the base of the device. Boron is used as the base dopant in these transistors having also highly doped regions below base contacts. Irradiations with neutrons with energies distributed from thermal to fast show that gain degradation adds up as Δ(1/β)=k<sub>T</sub>·Φ<sub>T</sub>+k<sub>eq</sub>·Φ<sub>eq</sub>.
    IEEE Transactions on Nuclear Science 09/2004; · 1.22 Impact Factor
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    ABSTRACT: Radiation damage caused by neutrons in DMILL npn bipolar transistors was measured. Transistors were exposed to neutrons with different fast-to-thermal flux ratios in the reactor in Ljubljana to fluences up to 5×1014n/cm2. Degradation of transistor common emitter current gain was measured as the function of fluence. Large degradation caused by thermal neutrons (E
    Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 01/2004; 518(1):474-476. · 1.14 Impact Factor
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    ABSTRACT: DMILL bipolar transistors (npn) were exposed to thermal and fast neutrons to fluences up to 6·10<sup>14</sup> n/cm<sup>2</sup>. Transistor common emitter current gain (β = I<sub>collector</sub>/I<sub>base</sub>) was measured after irradiations. It was found that beta degradation scales as Δ1/β = k<sub>T</sub>·Φ<sub>T</sub> where Φ<sub>T</sub> is the fluence if transistors are irradiated with thermal neutrons and as Δ1/β = K<sub>eq</sub>·Φ<sub>eq</sub>, where Φ<sub>eq</sub> is 1 MeV equivalent fluence if transistors are irradiated with fast neutrons behind Cd shield. Large damage factor K<sub>T</sub> ∼ 3·K<sub>eq</sub> was measured. Thermal neutrons don't have sufficient energy to displace a Si atom. Their damage mechanism is therefore identified with <sup>10</sup>B(n, α)<sup>7</sup>Li reaction from which energetic α and Li particles produce damage in the base of the device. Boron is used as the base dopant in these transistors having also highly doped regions below base contacts.
    Nuclear Science Symposium Conference Record, 2003 IEEE; 11/2003