Y掺杂Al_2O_3高k栅介质薄膜的制备及性能研究  

Fabrication and properties of the Y-doped Al_2O_3 high-k gate dielectric films

作　　者：郭得峰[1] 耿伟刚[1] 兰伟[1] 黄春明[1] 王印月[1] 

机构地区：[1]兰州大学物理系

出　　处：《物理学报》2005年第12期5901-5906,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:50272027)资助的课题.~~

摘　　要：利用射频反应共溅射方法制备了Y掺杂Al2O3电介质薄膜,用掠入射x射线衍射检测了薄膜的结构,用高分辨率扫描电子显微镜(HRSEM)、原子力显微镜(AFM)观察了薄膜断面和表面形貌,用高频C_V和变频C_V及J_V测量了样品的电学特性.结果表明,Y的掺入使电介质薄膜的介电常数k有了很大提高(8.14—11.8),并体现出了较好的介电特性.分析认为与氧具有较大电负性差的Y离子的加入,增大了薄膜中的金属—氧键(M—O)的强度;同时,Y的加入使Al2O3的结构和原子配位发生了改变,从而提高了离子极化对薄膜介电常数的贡献.退火前后的XRD谱均显示薄膜为非晶态;HRSEM断面和AFM形貌像显示所制备的薄膜非常平整,能够满足器件要求.Y-doped Al2O3 dielectric films have been fabricated by reactive radio frequency co-spnttering method. Grazing angle incidence x-ray diffraction results show that the as-deposited and annealed films are amorphous. High resolution scanning electron microscope and atomic force microscope have been applied to observe the cross-section and the surface morphology of the thin films. The electric C- V and I- V characteristics were measured at high and variable frequency, respectively. It was found that the dielectric constant k of the films increases remarkably （from 8.14 to 11.8） with increasing Y-doping concentration. The Y-O bond is stronger than Al-O due to the obvious difference in electro-negativity between the two bond members, which enhanced the ionic polarization in the thin films leading to an increase of the dielectric constant. It was supposed that the presence of Y ions changed the structure and atomic coordination of Al2O3 . The films were very smooth which meets the requirements of the device.

关 键 词：高K栅介质 掺杂氧化铝 射频反应溅射 

分 类 号：O484[理学—固体物理]