An internal calibration technique for pseudobinary systems by auger electron spectroscopy

An internal calibration technique has been developed for the quantitative analysis of pseudobinary systems by means of Auger electron spectroscopy without the need for stan-dards of known composition. This technique has been used for analyzing PbO-In₂O₃ two-phase films and A1N-A1₂ O₃ , AlAs-GaAs, and GaP-InP solid solutions. The technique is applicable to systems of the type (AC_m) (BC_n)_1-x if the Auger intensities measured for elemens A, B, and C are given by the linear relationships I = xI_A ^**, I_B = (l-x)I_B ^*, and I_C = xI_C ^** + (l-x)I_{C C} ^* where I_A ^** and I_C ^** are the inten-sities for pure AC_m and I_B ^* and I* are the intensities for pure BC_n . To determine whether this criterion is satisfied, a series of Auger measurements is made on regions of dif-ferent composition within a single specimen (e.g., on speci-mens in which a concentration variation exists across the surface or surfaces exposed by repeated sputter-etching of a sample with an in-depth composition gradient), and plots of I_A vs I_B and I_C/I_B vs I_A/I_B are made. If these plots are linear over tne range of compositions investigated, it is assumed that the above linear relationships are valid over the whole range of the pseudobinary system. It is then possible to construct linear calibration plots of I_A, I_B , and I_C vs x for the whole composition range.