부산대학교 도서관

Focused Helium Ion Beam (FHIB) can process nanostructures with high resolution, but the damage caused by FHIB cannot be ignored, therefore quantitative modeling and calculation are needed. The damage of He+ mainly includes the amorphization of crystal materials and the helium bubbles produced by helium accumulation in processing materials. In this paper, a helium bubble evolution model based on the reaction rate theory is proposed, which can simulate the evolution process of helium bubble in the substrate. Under a certain dose and energy input, the evolution of helium bubbles at different depths can be calculated, and the size characteristics and concentration of helium bubbles at different depths in the substrate after processing can be obtained. At the same time, two sets of experiments experiments were carried out by helium ion microscopy. In the first set of experiments, silicon substrate was injected with He+ with dose of 6.25×1018He+/cm 2 and injection energy of 10kev, 15kev and 35kev. In the second set of experiments, silicon substrate was injected with He + at energy of 35keVand dose of2.5×1018He+/cm 2 , 5×10 18 He+/cm 2 , 6.25×10 18 He+/cm 2 . Finally, the experimental results are compared with the simulation results.