ION BEAM INDUCED INTERFACIAL AMORPHIZATION IN SiGe/Si

About 230 nm amorphous layers were created by 200 keV Ge+ ion beam in a single crystalline Si and single crystalline Si1-xGex/Si samples containing 10% germanium. Rutherford backscattering spectrometry (RBS) with channeling techniques revealed that for the Si1-xGex/Si sample where post-annealing for 10 minutes at 300 °C in a nitrogen atmosphere was carried out, there was no observable a/c interface movement after the following irradiation by 3.9 MeV Ge2+ ions to a dose of 7×1014 cm-2. On the other hand, for the Si1-xGex/Si sample which was not annealed, the high energy irradiation resulted in the amorphization from the amorphous/crystalline (a/c) interface in a layer-by-layer manner by about 60 nm, i.e. ion beam induced interfacial amorphization (IBIIA) was observed. Observation of the a/c interface movement beyond a heterointerface was difficult owing to the strong damage accumulation by the high energy bombardment. Under the same experimental condition as Si1-xGex/Si, IBIIA was not observed for the Si sample probably due to the lack of doses