Based on orientation selective epitaxy ͑OSE͒ of CeO 2 ͑100͒ and CeO 2 ͑110͒ layers on Si͑100͒ substrates by substrate bias control in reactive magnetron sputtering, we have found the OSE growth of CeO 2 ͑100͒ layers induced by electron-beam irradiation, instead of substrate bias. In order to improve crystalline quality and interfacial properties, growth parameters of incident electron energy and an oxygen flow rate are analyzed, including the effect of oxygen radical beams. The electron-beam-induced OSE method gives a way to two-dimensionally spatially varied OSE.Epitaxial cerium dioxide ͑CeO 2 ͒ layers on silicon substrates are of great interest due to favorable properties as an electronic material, for example, high dielectric constant of 26, high chemical stability, transmission in visible and IR regions, and high efficient UV absorption. Epitaxial CeO 2 layers on Si͑100͒ substrates usually grow with ͑110͒ orientation. 1-5 After the report on the CeO 2 ͑100͒ layer growth on Si͑100͒ substrates with atomically cleaned reconstructed surfaces by molecular beam epitaxy, 6 it was found that orientation selective epitaxy ͑OSE͒ of CeO 2 ͑100͒ and CeO 2 ͑110͒ layers on Si͑100͒ substrates were capable by controlling substrate bias and the growth rate in reactive magnetron sputtering. 7,8 The epitaxial relation model of CeO 2 ͑100͒ and CeO 2 ͑110͒ on Si͑100͒ has been proposed with CeSi 2 ͑100͒ layer as intermediate layer, 9 and it is reported that CeO 2 ͑110͒ is usually preferred from thermodynamical considerations. 10 This preferential orientation selectivity is thought to be due to surface potential modification by substrate bias. In our previous work, it was clarified that substrate bias of Ϯ15 V leads to the CeO 2 ͑100͒ layer growth, whereas CeO 2 ͑110͒ layers grow on nonbiased substrates. 7,8 It is noted that OSE is irrespective of surface potential bending directions, which gives us an idea of surface potential modification by irradiation of charged particles, electrons and/or ions.This OSE technology has a lot of possibilities for applications to device fabrication processes and for OSE of many other materials. For future sophisticated applications, it is desired to develop a new technology for two-dimensionally spatially varied OSE. This article describes a novel technology to realize spatially varied OSE utilizing low-energy electron-beam irradiation instead of substrate bias application. 11 Here we report the CeO 2 ͑100͒ layer growth in a lowenergy electron-beam-irradiated area on Si͑100͒ substrates and show optimization of growth parameters, such as incident electron energy, oxygen flow during reactive sputtering, and resistivity of Si substrates. Interfacial properties are investigated using cross-sectional transmission electron microscopy ͑XTEM͒. The effect of oxygen radical beams in reactive sputtering is also investigated compared with conventional reactive sputtering. ExperimentalSi͑100͒ wafers cut 52 ϫ 52 mm in size were chemically cleaned to make H-terminated surfaces by the following procedure: dipping...

Based on orientation selective epitaxy (OSE) of CeO 2 (100) and CeO 2 (110) layers on Si(100) substrates by substrate bias control in reactive magnetron sputtering, we have found OSE growth of CeO 2 (100) layers induced by electron beam irradiation, instead of substrate bias. In order to improve crystalline quality and interfacial properties, growth parameters of incident electron energy and an oxygen flow rate are analyzed, including the effect of oxygen radical beams. The electron beam induced OSE method gives a way to two dimensionally spatially varied OSE.