Argon Precursor Ion Implantation Used to Activate Boron Atoms in Silicon at Low Temperatures

Abstract

The two-step implantation of argon precursor ion (Ar + ) followed by boron ion (B + ) in single crystalline silicon at room temperature is discussed to activate boron implanted region by post heating at 300 followed by 400 o C. The implantation of Ar + at a dose of 6.0 × 10 13 cm −2 at 70 keV with a projected range R p (Ar) of 80 nm followed by B + at 1.0 × 10 15 cm −2 and 15 keV with R p (B) of 62 nm caused crystalline disordered states with the effective disordered amorphous depth A eff of 32 nm, while the post heating of 300 o C for 90 min followed by 400 o C for 30 min markedly decreased A eff to 1.8 nm. The effective recrystallization by the post heating promoted activation of doped region associated with decrease in the sheet resistivity to 189 /sq by the post heating. The activation ratio was estimated as 0.33 under the assumption of a hole mobility of 50 cm 2 /Vs in the boron implanted region.INDEX TERMS Activation, carrier density, carrier lifetime, defect, low temperature.