Vacancy-engineering implants for high boron activation in silicon on insulator

The formation of boron interstitial clusters is a key limiting factor for the fabrication of highly-conductive ultrashallow doped regions in future silicon-based device technology. Optimized vacancy engineering strongly reduces boron clustering, enabling low-temperature electrical activation to levels rivalling what can be achieved with conventional pre-amorphization and solid-phase epitaxial regrowth. An optimized 160-keV silicon implant in a 55/145nm silicon-on-insulator structure enables stable activation of a 500eV boron implant to a concentration ~ 5x1020cm-3.