Thermal spike analysis of ion-induced tracks in semiconductors

Track data reported in InP and GaAs are analyzed according to the analytical thermal spike model (ATSM) and good agreement with the predictions is found. The Gaussian width of the thermal spike is a(0) ≈ 11 nm compared to a(0) = 4.5 nm in insulators. When the ion velocity v_p is high (E > 8 MeV/nucleon), a similar fraction of the electronic stopping power S_e is transformed into thermal energy of the spike in insulators and semiconductors. The results show that - compared to insulators - v_p affects only slightly the track sizes in semiconductors, which is explained qualitatively by the Coulomb explosion mechanism. The reported correlation between the bandgap energy E_g and a(0) is completed with new data. The results of previous analyses of ion-induced tracks in InP by ATSM are discussed.