Hydrogen-induced splitting in silicon over a buried layer heavily doped with boron

Formation of interior hydrogen-passivated surfaces in hydrogen-implanted single-crystal Si containing a buried layer heavily doped with boron is investigated. With the use of the infrared absorption spectroscopy, it is shown that, upon annealing, the composition of hydrogen-containing defects in Si samples containing a buried heavily doped layer is the same as in Si samples that do not have such a layer. However, the presence of a heavily doped layer enhances the blistering and exfoliation of a thin silicon film from the Si sample, and the activation energies of the relevant processes change. Thus, the process of development of cavities in such layers changes upon thermal annealing. The depth at which hydrogen-passivated surfaces are formed corresponds to the projected range of H ions in Si, which also corresponds to the depth at which the B-doped layer is located. When a thin exfoliated film is transferred onto an insulator to form a silicon-on-insulator structure, the surface roughness of the film decreases by a factor of 2–5.