Time-of-flight SIMS depth profiling of Na in SiO2 glass using C60 sputter ion beam

A depth profile analysis of SiO2 glass ion implanted with Na-23(+) was carried out on a time-of-flight secondary ion mass spectrometry (ToF-SIMS) with O-X, Cs and buckminsterfullerene (C-60) ion sputtering. The Na migration in SiO2 glass during both analysis process and sputter process was investigated under the various operating conditions. During the analysis process, Na-23(+) intensity stayed constant on the dose density of the Bi primary ion regardless of the conditions and went up using higher primary ion current. The Na profile in SiO2 glass similar to that of the Lindard-Scharff-Schiott theory was successfully acquired by the use of C-60 ion sputtering regardless of the operating conditions. It is considered that Na does not migrate during the sputter process with C-60 sputter ion beam. In addition, the detection limit of Na depth profile with C-60 ion sputtering was almost the same with existing dynamic SIMS analysis with Cs primary ion. Thus, the ToF-SIMS with C-60 ion sputtering is shown to be more versatile than the existing method by avoiding the necessity to optimize the operating conditions. Copyright (C) 2012 John Wiley & Sons, Ltd.