[20a-H113-1~12] 15.8 Crystal evaluation, impurities and crystal defects

[20a-H113-6] First-principles calculations on the stability of the vacancy cluster around n-type dopants in silicon

〇Hiroki Kawai¹, Yasushi Nakasaki¹, Takahisa Kanemura² (1.Toshiba R&D, 2.Toshiba S&S)

Keywords:vacancy,dopant,first-principles calculation

We investigated the mechanism of dissociation of the complex of divacancy V₂ and n-type dopants P and As in silicon by means of first-principles calculations. It was found that the total activation energy for releasing a V is almost same in both cases. The complex PV₂, however, dissociates into PV+V in a two-step process via metastable state VPV' with lower activation energies. On the other hand, the complex AsV₂ should dissociate in a one-step process with higher activation energy than that for the two-step process for PV₂. Our result suggests that As-doping into Si makes the vacancy cluster more stable and promotes clustering than P-doping.