VAMAS round robin study to evaluate a correction method for saturation effects in DSIMS

Recently, dynamic SIMS (D-SIMS) is being used to analyze ions simultaneously over a wide range of concentrations, from matrix level to extremely low (ng g-1). However, D-SIMS detectors, which are mostly used in pulse counting systems, have problems with detector saturation. Thus, the ion intensities of SIMS must be corrected in their high-intensity region. It has been reported that the approximation intermediate extended dead-time model (a-IED model) can be used to correct saturated intensity in the higher region better than can the conventional model. In this study, we evaluated the usefulness of the a-IED model to correct partially saturated and saturated intensities for magnetic-sector-type D-SIMS and quadrupole-type D-SIMS for the effects of dead time. Nine organizations from five countries participated in this project. Analyzed specimens were an arsenic-implanted silicon wafer and a diffused BN onto Si wafer. The instruments used to analyze arsenic-implanted samples were five quadrupole-type SIMS and four magnetic-sector-type SIMS. The instruments used to analyze the BN-diffused samples were three quadrupole-type SIMS, four magnetic-sector-type SIMS, and one time-of-flight-type SIMS. We validated the usefulness of the a-IED model to correct saturated intensities for all SIMS in this round-robin test. The optimum extension parameter ρ tends to be affected by the ratio of the maximum reliable intensity to the maximum intensity.