Heteroepitaxial Si/ErSi2/Si structures grown in high vacuum

Buried ErSi2 layers were grown in high vacuum (10(-8) Torr) on both (Ill)and (100) Si substrates. ErSi2 layers were grown by evaporation of Er and Si onto the Si substrate at 450 degrees C and subsequent annealing for 30 min at 800 degrees C. The top Si layer was formed by evaporation of Si onto the ErSi2 layer at 450 degrees C and subsequent annealing at 550 degrees C for 30 min. The Si/ErSi2/Si structures were characterized by X-ray diffraction and electron microscopy. Transmission electron microscopy characterisation revealed that the ErSi2 and top Si layers were grown epitaxially on (111) Si, were continuous and of high crystalline quality. Layers grown on (100) Si were epitaxial as well, but of inferior crystalline quality.