Impact of the Ge concentration on the Ge-ionisation probability and the matrix sputter yield for a SiGe matrix under oxygen irradiation

As SiGe becomes a building block of advanced devices, depth profiling of SiGe gains in importance, requiring an understanding of its basic behavior under oxygen bombardment. In this study, the sputter yield and ionization probability of Si and Ge sputtered from SiGe-substrates are studied as a function of the incidence angle. The altered layer formation and the element redistribution are studied with in situ sputter/RBS and the oxidation of the bombarded SiGe surface is analyzed with XPS. The results show that the altered layer formation in the SiGe system is much more complex than in the Si case and strongly dependent of the incident angle/primary energy. In addition to sputter related effects, thermodynamics and volatility of the Geoxide are important mechanisms. # 2004 Elsevier B.V. All rights reserved