Epitaxial, high-K dielectrics on silicon:: the example of praseodymium oxide

We show the first results for crystalline growth oh praseodymium oxide on Si as a potential high-K dielectric with very promising electrical properties. All layer growth experiments were performed using solid source molecular beam epitaxy. The initial growth phase was studied rising scanning tunneling microscopy. On Si(001) oriented surfaces, crystalline Pr2O3 grows as (110)-domains, with two orthogonal in-plane orientations. Epitaxial silicon overgrowth seems to be impossible. We obtain perfect epitaxial growth on Si(111). These layers can also be overgrown epitaxially with silicon. Finally, we show that the structural quality of epitaxial grown Pr2O3 on Si(001) degrades when the film is exposed to air due to silicon oxide formation at the interface based on oxygen indiffusion. However. it can be stabilized by capping with Si. (C) 2001 Elsevier Science Ltd. All rights reserved.