Initial Stage and Growth Process of Ceria, Yttria-Stabilized-Zirconia and Ceria-Zirconia Mixture Thin Films on Si(100) Surfaces

Abstract

Initial stages and growth processes of ceria ( CeO2), yttria-stabilized-zirconia (YSZ) and ceria-zirconia mixture ( Ce·ZrO2) thin films on Si(100) surfaces were studied in conjunction with O2 pressure. We showed that (110)-oriented films of CeO2, YSZ and Ce·ZrO2 grew obeying the arrangements of Si atoms in (2×1) or (1×2) structures on a Si(100) surface under about 5×10-7 Torr O2 gas at about 900° C. On the other hand, under 1×10-5 Torr O2 gas, (111)-oriented CeO2 polycrystal films grew because of formation of Ce2O3 and Si O2 layers at the interface between CeO2 and Si(100). Furthermore, the (100)-epitaxial YSZ and Ce·ZrO2 films grew, reducing the SiO2 layer on Si(100) under 1×10-5 Torr O2 gas. We attempted to explain these processes in terms of standard formation enthalpies of CeO2, Ce2O3, ZrO2 and SiO2.

High-temperature in situ Cross-sectional Transmission Electron Microscopy Investigation of Crystallization Process of Yttrium-stabilized Zirconia/Si and Yttrium-stabilized Zirconia/SiOx/Si Thin Films

“…[1][2][3][4][5][6][7] It has several excellent properties: a relatively highdielectric constant (∼25, so-called high-K material), an interdiffusion barrier, low-leakage current, a wide band gap (∼5.6 eV), an adequate band offset with Si (1.4 eV), thermal and chemical stability, epitaxial growth on a Si substrate, and others. [1][2][3][4][5][6][7] It has several excellent properties: a relatively highdielectric constant (∼25, so-called high-K material), an interdiffusion barrier, low-leakage current, a wide band gap (∼5.6 eV), an adequate band offset with Si (1.4 eV), thermal and chemical stability, epitaxial growth on a Si substrate, and others.…”

Electron-beam-assisted evaporation of epitaxial CeO2 thin films on Si substrates

“…In the course of the investigation on the epitaxial growth of CeO 2 layers on Si substrates, [1][2][3][4][5][6][7][8][9][10][11][12] it was found that although high-quality CeO 2 ͑111͒ layers grow on Si͑111͒ substrates at low temperatures, such as room temperature, 7 200°C, 3 and 300°C, 8 CeO 2 layers grown on Si͑100͒ substrates have a ͑110͒ orientation and require a substrate temperature of ϳ820°C. Low-temperature processes are strongly desired for microelectronic applications, such as miniaturized stable capacitors, silicon-on-insulator structures, and buffer layers between high-temperature superconductors and substrates.…”

CeO2 Thin Films as Buffer Layers for Si/YBCO Integrated Microelectronics

“…Many attempts have been tried to obtain good quality YBa 2 Cu 3 O 7-x (YBCO) films on Si substrates, with the aim of taking advantage from the properties of both materials, but interdiffusion reactions and a poor lattice and thermal expansion coefficient matching require the use of a buffer layer at the semiconductor/superconductor interface. Yttria-stabilized zirconia (YSZ), Y 2 O 3 , MgO, SrTiO 3 , CeO 2 and their combinations have been proposed and used as buffer layers in the case of Si/YBCO systems [4][5][6][7][8][9][10]. In this paper we will present results concerning the deposition and the study of Si/buffer-layer system, when conventional substrates, magnetron sputtering technique and post-deposition annealing treatments are employed.…”