Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China. IHP, Im Technologiepark 25, D-15236 Frankfurt (Oder), Germany.
Nanotechnology. 2017 May 26;28(21):215702. doi: 10.1088/1361-6528/aa6cd9. Epub 2017 May 2.
Unveiling the physical nature of the oxygen-deficient conductive filaments (CFs) that are responsible for the resistive switching of the HfO-based resistive random access memory (RRAM) devices represents a challenging task due to the oxygen vacancy related defect nature and nanometer size of the CFs. As a first important step to this goal, we demonstrate in this work direct visualization and a study of physico-chemical properties of oxygen-deficient amorphous HfO by carrying out transmission electron microscopy electron holography as well as energy dispersive x-ray spectroscopy on HfO/HfO bilayer heterostructures, which are realized by reactive molecular beam epitaxy. Furthermore, compared to single layer devices, Pt/HfO/HfO /TiN bilayer devices show enhanced resistive switching characteristics with multilevel behavior, indicating their potential as electronic synapses in future neuromorphic computing applications.
揭示负责基于 HfO 的电阻式随机存取存储器 (RRAM) 器件电阻切换的缺氧导电丝 (CF) 的物理性质是一项具有挑战性的任务，这是由于 CF 的氧空位相关缺陷性质和纳米尺寸。作为实现这一目标的重要第一步，我们通过在反应分子束外延中实现的 HfO/HfO 双层异质结构上进行透射电子显微镜电子全息术以及能量色散 X 射线光谱，来直接观察和研究缺氧非晶 HfO 的物理化学性质。此外，与单层器件相比，Pt/HfO/HfO/TiN 双层器件具有增强的电阻开关特性和多级行为，表明它们在未来神经形态计算应用中作为电子突触的潜力。
