CeO_2掺杂对HfO_2栅介质电学特性的影响

Influence of CeO_2-Doping on Electrical Properties of HfO_2 Gate Dielectrics

采用磁控共溅射的方法在p-Si(100)衬底上沉积了掺杂和不掺杂CeO2的HfO2薄膜。通过X射线光电子能谱(XPS)研究了薄膜中元素的化学计量比及结合能,制备MOS结构并对漏电流及电容等电学性能进行表征。结果表明,掺入CeO2后,整个体系的氧空位生成能增大,氧空位数目减少,漏电流较纯HfO2下降了一个数量级,满足作为高k材料的要求。

CeO2-doped HfO2（CDH） thin films were deposited on p-Si substrates by RF magnetron co-sputtering.The film thickness was measured by surface profiler.The binding energy of elements was characterized by X-ray photoelectron spectroscopy（XPS）.MOS structures were made to characterize the leakage current and capacitance.XPS analysis of Hf 4f and O 1s confirmed that the Hf-O binding energy increased after doping CeO2.This resulted in the increase of the oxygen vacancy formation energy and the reduction of the concentration of oxygen vacancy.The leakage current density of CDH film was about one order of magnitude lower than that of HfO2 film.CDH film can meet the requirements of high-k application.