Ion beam induced epitaxial crystallization of buried SiC layers in silicon

The ion beam induced crystallization of buried amorphous SiC layers in silicon is studied by cross-sectional transmission electron microscopy as a function of dose, dose rate, target temperature and substrate orientation. For this purpose homogeneous, crystalline, buried SiC layers were formed in (100) and (111)Si by ion beam synthesis. The resulting Si/SiC/Si layer systems were irradiated with 2 MeV Si+ ions at 300 K to amorphize the buried carbide layer without changing its chemical composition or damaging the Si top layer seriously. The amorphization process as well as the amorphous state of the SiC are considered in detail In order to achieve ion beam induced epitaxial crystallization (IBIEC), layer systems were irradiated with 800 keV Si+ ions at 320 and 600 degrees C. It is demonstrated that IBIEC works well on buried SiC layers and results in a single phase heteroepitaxial recrystallization at target temperatures considerably below those necessary for thermal annealing. The IBIEC process starts from both SiC/Si interfaces with different crystallization rates. Depending on irradiation conditions, it may be accompanied by heterogenous nucleation of poly-SiC as well as interfacial layer-by-layer amorphization.