Counter-oxidation of superficial Si in single-crystalline Si on SiO2 structure

This work proposes an oxidation mechanism for single-crystalline Si overlying a buried SiO2 layer (SOI wafer). Experimental results show that not only the surface oxide but also the buried oxide layer of the SOI wafer grows during the thermal oxidation process. The oxidation behavior is analyzed with a simple model including oxygen diffusion through the superficial single crystalline Si layer, which agrees well with the experimental data. Furthermore, oxygen penetration through the superficial Si layer is verified by oxidation experiments using isotope oxygen.