SPUTTER PROFILING OF ALGAAS GAAS SUPERLATTICE STRUCTURES USING OXYGENAND ARGON IONS/

Broadening of Al sputter profiles in AlxGa1-xAs/GaAs structures has be en investigated using secondary ion mass spectrometry. The depth profi ling was carried out with O-32(2)+ ions and Ar-40+ ions using net prim ary energies of 1.8, 2.2, 3.2 and 5.7 keV. The decay lengths of the Al profiles show a pronounced increase with increasing sputtering ion en ergy caused by ballistic mixing. Moreover, in the O2+ case the lambda- values degrade with eroded depth, indicating that beam-induced surface roughening takes place during profiling and in particular, this holds for high x-values. The results are discussed in terms of a semi-empir ical model for ion-beam-induced broadening developed by Zalm and Vriez ema.