Impact of Heavy Ion Energy on Charge Yield in Silicon Dioxide

The impact of heavy ion energy on charge yield in silicon dioxide was investigated by irradiating power VDMOSFETs with heavy ions at energies from 3 to 25 MeV/amu. The ion charge yield was determined by analyzing the gate voltage shifts of power VDMOSFETs induced by irradiation with
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Co γ -rays and several different heavy ion species. A strong dependence of the charge yield on the ion energy is revealed. The charge yield at ion energy of 25 MeV/amu is greater by nearly an order of magnitude than that at the ion energy of 3 MeV/amu. The results are consistent with simulations of heavy ion track structures for low- and high-energy ions.