Microstructure and electrical properties of CeO2 ultra-thin films for MFIS FeRAM applications
来源期刊:中国有色金属学报(英文版)2007年增刊第1期(Part ⅡB)
论文作者:唐明华 周益春 郑学军 魏秋平 成传品 叶志 胡增顺
文章页码:741 - 746
Key words:CeO2 thin film; RF magnetron sputtering; microstructure and electrical properties; MFISFETs memory applications
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.
基金信息:the Cultivation Fund of the Key Scientific and Technical Innovation Projects, Ministry of Education of China
the Open Project Program of LDMAT (Xiangtan University), Ministry of Education, China