AN INVESTIGATION OF SI0.5GE0.5 ALLOY OXIDATION BY HIGH-DOSE OXYGEN IMPLANTATION

An attempt to implant a high dose (up to 1.8 x 10(18) cm-2) of O+ ions into a Si0.5Ge0.5 alloy grown by molecular beam epitaxy (MBE) was made in this work, and the oxidation of the alloy by the implantation before and after thermal treatment was studied using X-ray photoelectron spectroscopy (XPS). The changes of the composition distribution in the sample were observed from the XPS depth profiles. The chemical states of Si and Ge as well as the location of their oxides were obtained from the spectrum fitting. The results indicate that compared to the implantation made on single crystal Si or Ge, this alloy seems to have more in common with the bulk Si and the reason is attributed to the different reactivities between Si and Ge with oxygen and the different stabilities of their oxides. A possible way to improve the experiment to achieve the SIMOX (separation by implanted oxygen) structure in this material is also suggested