Raman scattering studies of ion beam induced mixing at the amorphous germanium/crystalline silicon interface

Abstract

Thin layers of amorphous germanium vacuum deposited onto a 〈111〉 surface of crystalline silicon were irradiated with a Kr+ ion beam to produce an amorphous Si-Ge alloy at the interface. Raman scattering measurements were performed on these films both before and after the ion irradiation. The vanishing of the strong Si-Si lattice mode near 521 cm−1 and an appearance of the localized Si-Ge vibrational mode near 375 cm−1 in the Raman spectra of ion-irradiated films are correlated to the formation of an amorphous alloy of probable composition of Si0.2Ge0.8 at the interface.