Calibration of Phosphorus Implantation Dose in Silicon by Radiochemical Neutron Activation Analysis

Abstract

AbstractA radiochemical neutron activation analysis (RNAA) procedure has been developed, critically evaluated, and shown to have the necessary sensitivity, chemical specificity, and matrix independence to certify phosphorus at ion implantation levels. 32P, produced by neutron capture of 31P, is chemically separated from the sample matrix, and measured using a beta proportional counter. Analysis of 12 pieces of a silicon wafer, implanted at a nominal dose of 8.5 x 1014 atoms·cm-2, yielded a phosphorus concentration of (8.30 ± 0.16) x 1014 atoms·cm-2 (expanded uncertainty), in agreement with a consensus value of (8.23 ± 0.33) x 1014 atoms·cm-2 (1s uncertainty) determined from a round robin SIMS investigation. The relative standard deviation of < 2 % is suitable for certification of a Standard Reference Material.