Characterization of all-chromium tunnel junctions and single-electron tunneling devices fabricated by direct-writing multilayer technique

We report about the fabrication and analysis of the properties of Cr/CrOx/C r tunnel junctions and single-electron tunneling transistors, prepared by d ifferent variants of direct-writing multilayer technique. In all cases, the chromium oxide tunnel barriers were formed in air under ambient conditions . From the experiments on single junctions, values for the effective barrie r height and thickness were derived. For the all-chromium single-electron t unneling transistors, we achieved minimal junction areas of 17x60 nm(2) usi ng a scanning transmission electron microscope for the e-beam exposure on S i3N4 membrane substrate. We discuss the electrical performance of the trans istor samples as well as their noise behavior. (C) 1999 American Institute of Physics. [S0021-8979(99)03724-X].