中國有色金屬學報(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 17 Special 1 November 2007 |
WEI Qiu-ping(魏秋平)3, CHENG Chuan-pin(成傳品)1, 2, YE Zhi
（1. Faculty of Materials and Optoelectric Physics, Xiangtan University, Xiangtan 411105, China;
2. Key Laboratory of Low Dimensional Materials and Application Technology, Ministry of Education,
Xiangtan University, Xiangtan 411105, China;
3. School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:A detailed investigation about the dependence of microstructure and electrical properties on annealing temperature was carried out for cerium oxide(CeO2) ultra-thin films (18 nm to 110 nm) on n-type Si(100) substrates by RF magnetron sputtering. Substrate temperature was kept constant at 400 ℃ for all samples. The as-deposited films were subsequently annealed in air ambient at 700, 800 and 900 ℃ for 1 h respectively. The crystallinity and surface morphology of the CeO2 films were analyzed with X-ray diffractometer(XRD), scanning electron microscope(SEM), atomic force microscope(AFM) and Raman scattering measurement. Electrical properties of the Au/CeO2/Si/Au structure were examined by high frequency capacitance—voltage (C—V) characteristics at 1 MHz and leakage current density—electric field (J—E) characteristics. A Raman peak of the CeO2 thin films was seen at 463 cm−1. From C—V data, these films exhibit dielectric constants ranging from 18 to 23, the hysteresis width (ΔVFB) ranging from 0.015 V to 0.12 V and the density of trapped charges ranging from 1.45×1011 to 3.01×1011 cm−2. A leakage current of 4.75×10−8 −9.0×10−7 A/cm2 at 2 MV/cm was observed. The experimental results show that the CeO2 buffer layers are suitable for non-volatile metal- ferroelectric-insulator-semiconductor(MFIS) structure field-effect-transistors(FETs) memory applications.
Key words: CeO2 thin film; RF magnetron sputtering; microstructure and electrical properties; MFISFETs memory applications
