摘要
通过精确控制在Pt衬底上制备NiOx薄膜的工艺过程,制备出阻值窗口增大5倍以上,高低阻态稳定的TiN/NiOx/Pt结构阻变存储器.研究发现,NiOx薄膜的多晶态结晶结构和化学组分,尤其是Ni元素的化学态,是影响NiOx阻变存储器阻值窗口和稳定性的主要因素.X射线光电子能谱和X射线多晶体衍射测试结果表明,当NiOx薄膜中间隙氧或Ni2+空位增多时,Ni2+会被氧化成为Ni3+以保持电中性,Ni3+离子在材料中引入空穴导致P型氧化物NiO的漏电流增大.基于此机理,提出通过提高淀积温度、降低氧气分压的方法抑制NiOx薄膜中间隙氧或Ni2+空位的产生,降低TiN/NiOx/Pt结构阻变存储器关态漏电流,增大阻值窗口.这种基于工艺的性能增强方法,在NiOx阻变存储器实际应用中有良好前景.
Accurate process control of DC sputtering for NiOx thin film preparation results in TiN/NiOx/Pt resistive random access memory（RRAM） with better resistance stability and more than 5 times higher resistance ratio.It is found that,the polycrystalline nature and the chemical constituents,especially the chemical valence of Ni,are key factors to determine the resistance ratio and stability of NiOx RRAM.X-ray diffraction and X-ray photoelectron spectroscopy investigations indicate that,more interstitial oxygen atoms or Ni2＋ vacancies will lead to the oxidation of Ni2＋ to Ni3＋.While Ni3＋ will introduce holes into the film,resulting in the leakage current of P-type NiOx increased.Based on this mechanism analysis,a solution to suppress the leakage current is proposed,which increases the resistance ratio by increasing the deposit temperature and decreasing the oxygen partial pressure to effectively reduce the interstitial oxygen atoms or Ni2＋ vacancies.This process-based method will be promising for potential application of NiOx-based RRAM.
出处
《复旦学报（自然科学版）》
CAS
CSCD
北大核心
2010年第6期703-708,共6页
Journal of Fudan University：Natural Science
基金
国家自然科学基金(60776017)资助项目
关键词
阻变存储器
氧化镍
阻值窗口
稳定性
工艺控制
resistive random access memory
NiO
resistance ratio
stability
process control
