Fabrication and nuclear analysis of isotopic 14N and 15N ion-implanted silicon standards

The fabrication of reliable isotopic nitrogen standards is achieved in Si through 14N and 15N ion implantation. 60 keV 14N2+ and 15N2+ ions were implanted at 400 °C up to ∼60% peak atomic concentration, yielding nitrogen-saturated silicon layers as measured using resonant nuclear reaction analysis. No isotopic effect has been observed. The nitrogen standards are validated by measurements of stability under ion irradiation. No significant desorption of nitrogen is observed either under a 4He+ ion fluence of 3.36 × 1016 cm−2 or under a 1H+ ion fluence of 8.60 × 1017 cm−2, giving strong evidence that isotopic nitrogen standards can be achieved.