Defects and strain in H+ and He+ co-implanted silicon

In this paper we studied the process of blistering and exfoliation on the crystal silicon surface and evolution of defects and strain in crystal silicon caused by hydrogen and helium co-implantation. It is shown that H⁺ and He⁺ co-implantation would produce a synergistic effect, which decrease the total implantation dose greatly, compared with the single ion implantation. We have also presented the effect of co-implantation and analyzed the different role of H⁺ and He⁺ in the process of exfoliation during annealing. It seems that the essential role of hydrogen is to interact chemically with the defects in silicon and create the H-stabled platelets, while the role of helium is to effuse into these platelets and assert pressure on the inner surface of these platelets