Radiochemical Neutron Activation Analysis for Certification of Ion-Implanted Phosphorus in Silicon

A radiochemical neutron activation analysis procedure has been developed, critically evaluated, and shown to have the necessary sensitivity, chemical specificity, matrix independence, and precision to certify phosphorus at ion implantation levels in silicon. 32P, produced by neutron capture of 31P, is chemically separated from the sample matrix and measured using a (beta) proportional counter. The method is used here to certify the amount of phosphorus in SRM 2133 (Phosphorus Implant in Silicon Depth Profile Standard) as (9.58 +-0.16) × 10^14 atoms·cm-2. A detailed evaluation of uncertainties is given.