Gd2O3 grown on Si is a promising candidate for a very thin high-K material replacing SiO2 in future MOS devices. The cover picture shows cross sectional high-resolution transmission electron microscopy images which document the controlled growth of interface-free, thin and smooth layers right down to the atomic scale. Depicted on the lower left is a sample with a 5.3 nm thick Gd2O3 layer grown under optimized conditions on Si(001) by modified molecular beam epitaxy and covered by a Pt electrode. The image in the middle and the magnified part to the right demonstrate a Gd2O3/Si/Gd2O3 double-barrier structure grown on Si(111) by combined solid vapour phase epitaxy. An ultra-thin single-crystalline Si layer buried in a single-crystalline insulator matrix with sharp interfaces was obtained by this approach. More information on high-K materials selection, growth methods, electrical properties and possible applications is available in the Feature Article by H. J. Osten et al. (pp. 695–707). The first author is the Director of the Institute of Electronic Materials and Devices at the Leibniz University of Hannover, where he also holds a chair. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)