Vacancy Generation by Laser Preirradiation for Junction Leakage Suppression

Vacancy generation by laser preirradiation on silicon substrate before implantation for advanced junction engineering was demonstrated. Amorphized p⁺/n junction diodes subjected to preimplant laser irradiation show a twofold reduction on the off-state leakage current and a two-time improvement on the on-state current compared to control devices without any preirradiation. The defect-removal mechanism is achieved by the recombination of excess vacancies trapped at the maximum laser melt depth as a result of the molten silicon recrystallization with the implantation-generated interstitials. The effectiveness of laser-generated vacancies in annihilating residual defects is evident in the suppression of junction leakage current.