INFLUENCE OF SECONDARY ION ENERGY-DISTRIBUTIONS ON SIMS MATRIX ION INTENSITIES AND RELATIVE SENSITIVITY FACTORS IN THE SYSTEM GAAS GAALAS

SIMS investigations are presented on erosion rates, suited matrix ions for layer identification in layer systems of GaAs and GaAlAs depending on the Al concentration and the acceptable secondary ion energies using O2+ and Ar+ primary ions and positive secondary ions. The development of relative sensitivity factors of the doping elements Mg, Si, Cr, Zn, Ge, Sn is also measured depending on the Al concentration and the accepted secondary ion energy using O2+ bombardment. The SIMS measurements are shown to be very sensitive to the choice of position and width of the ion energy window. The investigations show partially considerable enhancement of the low-energy portion of the secondary ion energy distribution with increasing Al content, typical for this chemical element, especially between O and 20 at % Al. The higher-energy portion of the energy distributions is much less influenced by the Al content. © 1990.