Use of resonance ionization microprobe analysis for characterization of ultrashallow doping profiles in semiconductors

We have built an analytical time-of-flight instrument capable of sputter-initiated resonance ionization microprobe (SIRIMP) measurements. This instrument has the ability to obtain ultrashallow doping profiles with high depth resolution and dynamic range and virtually no matrix effects. The SIRIMP technique is especially valuable for ultratrace element analysis in samples where the complexity of the matrix is frequently a serious source of interferences. We describe the capability of the SIRIMP technique to quantitate with high accuracy and dynamic range dopant and impurity concentrations in silicon and silicon oxide samples at the 10(13)-10(20) level. For example, the depth profile for a Sb implant in silicon shows a dynamic range of greater than 10(7). Dynamic range and depth resolution, quantitation accuracy, and limitations will be discussed. (C) 1996 American Vacuum Society.