date:IBM Res GmbH, Zurich Res Lab, CH-8803 Ruschlikon, Switzerland; Politecn Milan, LNESS, Dipartimento Fis, I-22100 Como, Italy; Ecole Polytech Fed Lausanne, IPMC, CH-1015 Ecublens, Switzerland
The growth of epitaxial SrTiO3 on silicon relies on the preparation of a template layer consisting of a mixture of barium oxide and strontium oxide, (Ba,Sr)O. In this letter, the limited thermal stability of this template layer is demonstrated. X-ray photoemission spectroscopy measurements reveal that both SrTiO3/(Ba,Sr)O and (Ba,Sr)O/Si interfaces are susceptible to chemical reactions upon thermal treatment to an extent that is correlated with the thermal budget. These results have strong implications on the overall viability of (Ba,Sr)O as template for the growth of crystalline oxides on Si.