The Role of a radial ion-track distribution in semiconductors studied by numerical simulations

Onoda, Shinobu; Hirao, Toshio; Oshima, Takeshi; Ito, Hisayoshi

The effects of radial ion track distribution on the unexpected noise (transient current) in semiconductors by a high energy heavy ion strike have been studied. The measured transient currents were compared with the numerically observed one, which was calculated with the wide variety of ion track radii. In the case of low energy (several MeVs) ion, the calculated transient currents were independent of the radial track distribution. However, in the case of high energy (several hundreds of MeVs) ion, the transient currents strongly depend on the radial track distribution. This difference is interpreted in terms of the carrier concentration at the core of track, resulting in the extremely different carrier mobility. When the radius of ion track used in numerical simulator was shorter than, or equivalent to, the penumbra radius, the reasonable agreement was found between experimental and calculated transient currents.