The Application of Ion Implantation to Quantitative SIMS Analysis
The applicability of SIMS analysis for the micro and depth characterization of semiconducting matrices has been widely realized in recent years. Efforts for quantification have been hindered, however, by the absence of a workable theoretical model of the sputtering ionization process and more critically by the unavailability of homogeneously distributed standard materials for elements present in trace concentrations. The use of quantitative ion implantation and its particular applicability to single crystal semiconductors offers a solution to this difficulty.
Ion implant standards will be discussed in tenns of their unique properties for SIMS analysis. The advantages of this method for use as both external and internal standards will be presented as well as the limitations inherent in the technique. The methods of concentration calculations both before implantation and after SIMS analysis will be given and the error factors discussed.
The use of such standards has allowed us to systematically study the effects of matrix composition on ionization probabilities for a wide range of elements. Correlations of matrix properties to the ion yield will be presented for Si, Ge, GaP, GaAs and InP substrates.