Defect engineering in the initial stage of SIMOX processing

Defect engineering for SiO2 precipitation was investigated during ion beam synthesis in the first stage of SIMOX fabrication. Vacancy-type defects were created in Si: (i) a buried nanocavity layer was pre-fabricated by He implantation and subsequent annealing, and (ii) excess vacancies were generated during oxide synthesis by an additional simultaneous high-energy Si irradiation.
A narrow nanocavity layer was found to be an excellent nucleation site that favors effectively the SiO2 formation. Such a cavity layer must be adjusted to the excess vacancy profile of the O implant. The excess vacancy generation by simultaneous dual implantation minimizes the defect production in Si. However, it is inappropriate to form a narrow oxide layer due to the too broad distribution of excess vacancies.