Is there an influence of ion-beam-induced interfacial amorphization on the a/c-interface depth in silicon at common implantation energies?

Abstract

Ion-beam-induced interfacial amorphization (IBIIA) of Si, i.e. the growth of an existing amorphous layer upon ion bombardment, has previously been demonstrated for high-energy (MeV) heavy ions. Using transmission electron microscopy we show that IBIIA cannot be observed for sub-MeV energies at liquid nitrogen temperature, while it still exists at room temperature, in spite of the fact that for MeV implants the IBIIA rate increases with decreasing temperature. The experimental conditions investigated are 60keV Si and 560keV Ge implants. We corroborate the liquid nitrogen results by molecular dynamics simulations. The observation of IBIIA at room temperature for sub-MeV energies suggests that it should be considered for modeling the position of the a/c-interface in amorphizing implants.